Musa ibn Ja'far al-Kazim (Arabic: مُوسَىٰ ٱبْن جَعْفَر ٱلْكَاظِم, romanized: Mūsā ibn Jaʿfar al-Kāẓim; 745–799) was a descendant of the Islamic prophet Muhammad and the seventh imam in Twelver Shia Islam. Musa is often known by the title al-Kazim (lit. 'forbearing'), apparently a reference to his patience and gentle disposition. He was born in 745 CE in Medina to Ja'far al-Sadiq, the sixth Shia imam, who died in 765 without publicly designating a successor to save his heir from the wrath of the Abbasid caliphs. The subsequent crisis of succession was eventually resolved in favor of al-Kazim, with a dissenting group, now known as the Isma'ilis, separating from the mainstream Shia.

After the death of al-Sadiq, Musa al-Kazim remained in Medina, where he kept aloof from politics and devoted himself to religious teachings. He was nevertheless tightly restricted by the Abbasid caliphs and spent much of his adult life in their prisons. To counter these restrictions, he established an underground network of local representatives to organize the affairs of his followers across the Abbasid empire and to collect their religious donations. His final imprisonment, circa 795, ended with his death in 799 in a Baghdad prison, possibly poisoned at the instigation of the Abbasid caliph Harun al-Rashid. The shrine of al-Kazim and his grandson, Muhammad al-Jawad, is a popular pilgrimage destination for Twelver Muslims in Kazimayn, Baghdad.

Musa al-Kazim played a key role in eradicating extreme views and exaggerations (ghuluww) from Twelver thought. His answers to legal questions have survived in Wasiyya fi al-aql, and he is credited with numerous supplications. Musa al-Kazim is also revered for his piety in Sunni Islam and considered a reliable transmitter of prophetic sayings. He is a link in the initiatic Golden Chain in Sufism, and some Sufi saints are often associated with him. Various nonprophetic miracles are attributed to al-Kazim, often emphasizing his precognition. He was succeeded to the imamate by his son, Ali al-Rida.

Musa was probably born on 8 November 745 CE (7 Safar 128 AH). He was born either in Medina, or in nearby al-Abwa', located between Medina and Mecca. Alternative birth dates are September 745 and 746–747. His father was Ja'far al-Sadiq, a descendant of Ali ibn Abi Talib and Fatima, who were the cousin and daughter of the Islamic prophet Muhammad, respectively. Ja'far al-Sadiq was widely accepted as the legitimate imam by the early Shia community, who rejected the ruling Umayyad caliphs as usurpers. Musa's mother was Hamida Khatun, a Berber slave-girl. She was also known as al-Musaffat (lit. 'the purified'), a title which was perhaps a reference to her religious learning, as she is said to have taught Islamic jurisprudence to women in a seminary in Medina. Abd-Allah al-Aftah and Isma'il were the elder half-brothers of Musa, and Muhammad al-Dibaj was his younger full brother. Musa was about four years old when the Abbasid revolution overthrew the Umayyad Caliphate in 750. He continued to live in Medina under the authority of his father al-Sadiq, until the latter died in 765. Ja'far al-Sadiq was poisoned at the instigation of the Abbasid caliph al-Mansur (r. 754–775), according to the Shia.

After the death of al-Sadiq, Musa al-Kazim remained in Medina, where he stayed out of politics, similar to most of his predecessors. As with his father, al-Kazim instead taught religious sciences in Medina. Over time, he also established an underground network of representatives (wukala) to collect religious donations from his followers and organize their affairs.

The Abbasids, who claimed descent from Muhammad's uncle Abbas, had rallied the support of the Shia community against the Umayyads in the name of the family of Muhammad. But many Shias were disillusioned when the Abbasid al-Saffah (r. 750–754) declared himself caliph, as they had instead hoped for an Alid leader, one who had descended from Muhammad, that is, a descendant of his daughter Fatima and Ali ibn Abi Talib. The Abbasids soon turned against their former allies, and were generally hostile to the Shia imams, especially after the abortive 762–763 revolt of the Alid pretender Muhammad al-Nafs al-Zakiyya. Musa al-Kazim was contemporary with the Abbasid caliphs al-Mansur, al-Hadi, al-Mahdi, and Harun al-Rashid. Unlike his father, who often taught freely in Medina, al-Kazim was highly restricted by the caliphs, and spent much of his adult life in the Abbasid prisons in Iraq. By one Shia account, under the Abbasids' watchful eyes, al-Kazim even discouraged his followers from greeting him in public.

Shia sources blame the Abbasid caliph al-Mansur for the death of Ja'far al-Sadiq, who did not publicly designate an heir, likely fearing the Abbasid reaction. Shia sources report that the caliph ordered his governor of Medina to kill the heir to al-Sadiq, a plan that was thwarted when the governor found out that al-Sadiq had appointed four or five legatees. The resulting crisis of succession to al-Sadiq was ultimately resolved in favor of al-Kazim, who spent the first ten years of his imamate under al-Mansur. This succession crisis nevertheless weakened the mainstream Shia, which is perhaps why al-Mansur left al-Kazim relatively unmolested, while still keeping him under surveillance. This initial mild treatment of al-Kazim would not continue under future caliphs.

During the ten years of the reign of al-Mahdi, al-Kazim remained under surveillance in Medina. He was arrested at least once by the caliph, who around 780 briefly imprisoned him in the Abbasid capital of Baghdad. There Musa was placed in the custody of the prefect of police, al-Musayyab ibn Zuhayr al-Dabbi, who later became a follower of al-Kazim. According to the Sunni historian al-Tabari (d. 923), al-Mahdi had a dream in which Ali ibn Abi Talib berated him for imprisoning his progeny, which apparently compelled the caliph to set al-Kazim free, after he pledged not to revolt against the caliph.

Musa al-Kazim did not lend his support to the 786 revolt of the Alid pretender al-Husayn ibn Ali al-Abid, and a letter attributed to al-Kazim even warns al-Husayn about his violent death. The Shia imam was nevertheless accused of complicity by the Abbasid caliph al-Hadi, who was dissuaded from killing al-Kazim only by the intervention of the judge Abu Yusuf. The caliph died soon after, and thus al-Kazim survived. He then composed the supplication Jawshan (lit. 'coat of mail') in gratitude, according to the Shia jurist Ibn Tawus (d. 1266).

The persecution of the Shia reached a climax during the caliphate of Harun, who is said to have killed hundreds of Alids. Harun also arrested al-Kazim, brought him to Baghdad, and was apparently intent on killing him but then set him free as a result of a dream, it is said. Harun was perhaps provoked by an earlier incident, according to the Sunni historian Ibn Khallikan (d. 1282): When the two men visited the tomb of Muhammad in Medina, Harun, intent on showing his family ties to the prophet, had said, "Salutation unto thee, O prophet of God, unto thee who art my cousin!" Musa al-Kazim apparently countered with, "Salutation unto thee, O my dear father!" This angered Harun, who retorted, "O Abu al-Hasan [al-Kazim], such glory as thine is truly to be vaunted of!"

The final imprisonment of al-Kazim may have been plotted by Yahya ibn Khalid al-Barmaki, Harun's vizier. The vizier was reportedly threatened by the growing influence of Ja'far ibn Muhammad, who was entrusted with the caliph's son and heir, Amin. Yahya is said to have tipped the caliph about the secret Shia disposition of Ja'far and also suborned a relative of al-Kazim to testify that the imam secretly collected religious dues from the Shia. Alternatively, al-Kazim was imprisoned perhaps because the caliph felt threatened by the views of a disciple of al-Kazim, the theologian Hisham ibn al-Hakam, who argued for the right of al-Kazim to the caliphate, thus implying the illegitimacy of the Abbasids. In any case, Harun had al-Kazim arrested in 793, or in 795, and had him brought to Basra in Iraq, where he was imprisoned for a year under the custody of its governor, Isa ibn Ja'far ibn al-Mansur. Harun then ordered al-Kazim to be killed but Isa did not carry out the order, apparently being impressed by the piety of al-Kazim. Isa instead arranged for al-Kazim's house arrest in Baghdad under Fadl ibn al-Rabi' and then under Fadl ibn Yahya al-Barmaki. During his house arrest, however, al-Kazim likely continued to direct the Shia affairs. When Harun learned about this relatively comfortable conditions of al-Kazim, he gave Fadl a written order to kill the Shia imam. By one account, Fadl refused the order and was given a hundred lashes. Musa al-Kazim was then handed to al-Sindi ibn Shahik, the prefect of police in Baghdad, who is said to have poisoned the imam.

Musa al-Kazim died in 799 in the al-Sindi ibn Shahiq prison of Baghdad, after being transferred from one prison to another for several years. He may have been poisoned by order of the Abbasid caliph Harun, an order conveyed to al-Sindi through Yahya al-Barmaki, when he had visited the caliph in Raqqa to intercede for his son, Fadl. The latter had reportedly disobeyed caliph's earlier orders to kill al-Kazim. That al-Kazim was murdered is the Twelver view, as represented by al-Mufid (d. 1022), a prominent Twelver theologian. By contrast, al-Tabari does not mention the cause of al-Kazim's death, thus implying that al-Kazim died from natural causes, a view preferred by most Sunni authors. The date of al-Kazim's death is often given as 13, 31 August, or 1 September 799 (6, 24, or 25 Rajab 183 AH), while Twelvers annually commemorate this occasion on 25 Rajab.

Harun brought several public figures to examine al-Kazim's body and testify that he had died naturally. The caliph also publicly displayed the body of al-Kazim in Baghdad, perhaps to dispel the rumors that he had not died and would return as the Mahdi, the Messianic figure in Islam. Later al-Kazim was buried in the Quraysh cemetery in northwest Baghdad, which is now located in Kazimayn (lit. 'the two Kazims'), a city named after him and his grandson, Muhammad al-Jawad, who is buried next to him. At first a dangerous site for Shia visitors, the burial site in time became an important center for Shia pilgrimage. A shrine has stood over the two graves since the time of the Buyid dynasty (r. 934–1062), but the present complex dates to the Safavid monarch Isma'il (r. 1501–1524), the Twelver ruler of Iran. The shrine of al-Kazim has over time acquired a reputation as a place where prayers are fulfilled, that is, a gate to the fulfilment of needs (bab al-hawaij), as attested by the Sunni scholar al-Shafi'i (d. 820). Also buried there are a number of medieval Shia scholars, including the polymath Nasir al-Din al-Tusi (d. 1274).

After the death of al-Sadiq in 765, his following became fractured, for he did not publicly designate a successor to save his heir from the Abbasids' wrath. The majority of his followers, the antecedents of the Twelvers, ultimately accepted the imamate of his son al-Kazim, who also received the backing of some renowned students of al-Sadiq, including Hisham ibn al-Hakam and Mu'min al-Taq. However, instead of al-Kazim, many expected the next imam to be his elder half-brother, Isma'il, who predeceased his father. These were the antecedents of the Isma'ilis, some of whom waited for Isma'il to return as the Mahdi and the others instead accepted the imamate of his son Muhammad ibn Isma'il. When the latter died, some expected him to return as the Mahdi and others followed a line of imams who claimed descent from him. Even though the Isma'ilis were active against the Abbasids, they were of marginal importance until their political success much later: The Fatimid Caliphate was established in Egypt at the turn of the tenth century and the Qarmatians rose to power in Bahrain in the late ninth century. Their relations with the mainstream Shia were apparently tense at the time, as some have implicated them in the arrest of al-Kazim and the murder of some of his followers.

Isma'ilis believe that Isma'il was the designated successor, and this appears to be the general consensus of the early Shia sources as well. For the Isma'ilis, the death of Isma'il in the lifetime of al-Sadiq did not annul his divine designation (nass), as that would have contradicted their belief in the omniscience of God. By contrast, the early Twelvers explained any such changes in the divine will through bada', a notion similar to abrogation (naskh) in the Quran. Later Twelvers, such as al-Mufid, altogether rejected the claim that Isma'il was the designated successor of al-Sadiq. Historical evidence indeed suggests ties between Isma'il and radical Shias, of whom the quiescent al-Sadiq did not approve. Twelvers instead cite the qualifications of al-Kazim to support his fitness for the imamate after al-Sadiq. While the Twelvers and the Isma'ilis are the two sects that have survived, there were also additional branches that emerged after the death of al-Sadiq: After the death of al-Sadiq, some waited for his return as the Mahdi, but perhaps the majority of his followers initially accepted the imamate of his eldest surviving son, Abd-Allah al-Aftah. This group became known as the Fathiyya. Abd-Allah apparently lacked the scholarly prerequisites for the imamate and died a few months later without a male heir. His followers then mostly turned to al-Kazim, although for some time they still counted al-Aftah as their seventh imam. Some other followers of al-Sadiq turned to Musa's younger brother, al-Dibaj, who staged an unsuccessful revolt against the Abbasids in 815–816. Over all, it appears that many of those who had split off after the death of al-Sadiq eventually joined al-Kazim later.

The Abbasid caliphs tightly controlled the activities of al-Kazim, who consequently appointed a network of local representatives (wukala, sg. wakil) to organize the affairs of the Shia and collect their religious dues, particularly Khums (lit. 'one-fifth'). Extending throughout the Abbasid empire, this underground network was likely established by al-Kazim, while there is also some evidence that an earlier network might have existed under his predecessor, al-Sadiq. During the imamate of al-Kazim, new Shia centers were also established in the Maghreb and Egypt.

It appears that al-Kazim permitted cooperation with the Abbasids so long as it furthered the Shia cause. In particular, he might have allowed his companion Ali ibn Yaqtin to hold the vizierate to promote justice and social welfare, or perhaps to save other Shias in times of danger. In line with the principle of taqiya, al-Kazim even instructed Ibn Yaqtin not to practice the Shia ablution (wudu') to avoid the suspicion of the Abbasid ruler. In another Shia report, al-Kazim saves Ibn Yaqtin by instructing him to withhold some goods destined for him, thus foiling a plot aimed at exposing their personal ties. Ibn Yaqtin was nevertheless finally arrested, as part of the same campaign of arrests that led to the imprisonment and death of al-Kazim. He later died in prison. Historically, whether Ibn Yaqtin attained the vizierate office and for long enough to make any difference is uncertain. Some other Abbasid officials whose loyalty rested with al-Kazim were Abbas ibn Ja'far al-Ash'ath, governor of Khorasan, and Waddah (or Wadih), who was an official of the postal service (al-barid) in Egypt.

After the death of al-Kazim in 799, most Shias acknowledged his son, Ali al-Rida, as their imam. These Shias were the antecedents of the Twelvers, known at the time as the Qat'iyya because they confirmed the death of al-Kazim. By contrast, some followers of al-Kazim waited for his return as the Mahdi, citing a hadith ascribed to al-Sadiq to the effect that the seventh imam would be the Mahdi; these became known as the Waqifiyya (lit. 'those who stop'). Many of the Waqifiyya later returned to the mainstream of Shia, declaring al-Rida and his descendants as the lieutenants of al-Kazim. The Waqifiyya sect and its beliefs eventually disappeared, beginning in the ninth century. The Waqifiyya included the Bushariyya, named after Muhammad ibn Bashir, the Kufan exaggerator (ghali) who regarded al-Kazim as divine and claimed to be his interim successor. Ibn Bashir was later charged with heresy and executed by order of the caliph.

The formation of the Waqifiyya may have had a financial dimension, as some representatives of al-Kazim probably declared him the last imam just to avoid returning what was entrusted to them during the lifetime of al-Kazim. These rogue representatives included Mansur ibn Yunus al-Qurayshi, Ali ibn Abi Ḥamza al-Bata'ini, Ziyad ibn Marwan al-Qandi, Uthman ibn Isa al-Amiri al-Ruasi (Ruwasi), and Hayyan al-Sarragh, although al-Ruasi may have later turned possessions over to al-Rida. More broadly, the term Waqifiyya or Waqifite is also applied to any Shia group who denied or hesitated over the death of a particular imam, thus refusing to recognize his successors. The imamate of Ali al-Rida was not challenged by any of his brothers, even though some of them revolted against the Abbasids, including Ahmad ibn Musa.

Often viewed as evidence of his divine favor, various nonprophetic miracles (karamat, sg. karama) have been attributed to al-Kazim in Shia sources. Therein, he is considered knowledgeable of all languages, and this ability in Shia sources is not specific to al-Kazim. Indeed, a hadith attributed to al-Kazim counts this ability as a sign of the true imam. This also included the ability to communicate with animals, following the precedent of Surat al-naml, a chapter in the Quran, in which Solomon speaks with birds and ants. Musa al-Kazim is thus said to have prayed for a wild beast to ease the birthing pains of its partner. By other accounts, Musa spoke in his cradle, revived a dead tree with his touch, and brought back to life the dead farm animal of a poor family. By another account, al-Kazim showed to a disciple the spirit of al-Sadiq, who had died some years earlier, seated in the entryway to his house.

Musa al-Kazim and his father al-Sadiq successfully rooted out the belief in the imam's divinity from mainstream Shia thought, as evidenced by its absence in later mainstream Shia writings. Nevertheless, there remained at the time groups with extreme views (ghuluww) embedded within mainstream Shia. These Ghulat (lit. 'exaggerators') continued to believe in the divinity of the Shia imams. For instance, the Mufawwida believed that God had delegated (tawfiz) the affairs of this world to the prophet and the Shia imams. Such beliefs were also championed by al-Mufaddal ibn Umar al-Ju'fi, a financial agent of al-Kazim. However modern Shi'i scholars have accepted Mufaddal as a pious companion, and the works attributed to him false.

There is no evidence that any of the Shia imams personally subscribed to these extremist views.

By some Shia accounts, al-Kazim died for the sins of his followers. This is explained in a tradition attributed to him, "God became wrathful with the Shia, so he made me choose between them or myself and I shielded them, by God, with my soul." This tradition may also suggest al-Kazim's premonition about his own death. These sins may have been disloyalty (to the imam) and abandoning taqiya (religious dissimulation), according to the Twelver traditionist al-Kulayni (d. 941), who adds that the latter sin revealed the activities of al-Kazim and led to his imprisonment. Harun indeed carried out a campaign of arrests in 795 to decimate the underground network of local Shia representatives (wukala), which may have led to the final arrest of al-Kazim.

By some reports, al-Kazim had eighteen sons and twenty-three daughters, while other reports suggest thirty-three to sixty children. According to the historian D.M. Donaldson (d. 1976), these children were all sired with freed slaves (umm walads), including Najma (or Tuktam) who bore al-Kazim his son and successor, Ali al-Rida. Before he died in 818, al-Rida was briefly the heir to the Abbasid caliph al-Ma'mun (r. 813–833). Abbas, another son of al-Kazim, became the governor of Kufa. Three other sons—Zaid, Ibrahim, and Isma'il—participated in the unsuccessful 815 revolt of Abu al-Saraya against the Abbasids. The shrines of some of the children of al-Kazim are sites of pilgrimage in Iran, including those of Fatima al-Ma'suma in the city of Qom, Ali al-Rida in Mashhad, Husayn in Qazvin, and Ahmad in Shiraz. The Safavid dynasty (r. 1501–1736) in Iran also claimed descent from al-Kazim, though this claim has been questioned. His lineage may account for about seventy percent of the descendants of the prophet (the sayyids) in Iran. A report implies that al-Kazim allowed (at least one of the) women in his household to study religious sciences, despite outside objections.

Musa is often referred to as al-Kazim (lit. 'forbearing' or 'he who restrains his anger'), an honorific title suggesting mild manner and patience. For instance, he is said to have kindly treated an abusive opponent, who became an adherent in consequence. He was also known by the title al-Abd al-Salih (lit. 'the holy servant' or 'the righteous servant of God'). This title was a reference to his piety, for he is said to have spent most of his life in prayer and solitary contemplation. Among his predecessors, al-Kazim has been compared in benevolence and asceticism to Ali ibn Husayn al-Sajjad, the fourth of the Twelve Imams. The kunya of al-Kazim was Abu al-Hasan, the first, so as to distinguish him from the eighth and the tenth imams in Twelver Shia who shared the same kunya. Another kunya of al-Kazim was Abu Ibrahim.

The Sunni historian Ibn Khallikan (d. 1282) praises al-Kazim in his biographical Wafayat al-a'yan: "He [al-Kazim] entered one evening into the mosque of God's Apostle and, just as the night was setting in, he made a prostration [in worship] which lasted until the morning, and during that time he was heard to request without intermission, 'O thou who art the object of our fear! O thou whom it becometh to show mercy! Let thy kindly pardon be granted to me whose sin is so grievous!''' The same source extols al-Kazim as generous and benevolent, "When a man had spoken ill of him, he sent him a purse containing one thousand dinars," and, "He used to tie up in packets sums of three hundred, or four hundred, or two hundred dinars and distribute them in the city of Medina." Musa al-Kazim was also probably a gifted polemicist: The celebrated Sunni jurist Abu Hanifa (d. 767) was apparently once silenced by a young al-Kazim, while a group of Christians who came to dispute with him about religion subsequently came to accept Islam.

All successors of al-Sadiq, including al-Kazim, were largely removed from public life by the Abbasids, through imprisonment or surveillance. Musa al-Kazim nevertheless taught Shia beliefs, and played a key role in eradicating extreme views (ghuluww) from mainstream Shia thought. Some letters attributed to al-Kazim in his captivity years have survived, and his answers to legal questions are available in Wasiyya fi al-aql. He advised others that supplication (du'a') could avert even predestined calamities, and numerous supplications are credited to him. His saying, "The jurists (fuqaha, sg. faqih) who are believers (mu'min, i.e., Shia) are the citadels of Islam," has been reinterpreted in recent times to encourage an active social role for religious scholars.

Musa al-Kazim is revered in Sunni Islam and considered a reliable traditionist by Sunni scholars, including Ahmad ibn al-Hanbal (d. 855), who quotes from al-Kazim in support of the Alids. Some traditions attributed to al-Kazim were collected by the Sunni scholar Abu Bakr Muhammad ibn Abd-Allah al-Bazzaz (d. 965) in his Musnad al-Kazim, which is extant. Musa al-Kazim is also venerated among the Sufis. Among Sufi saints, Shaqiq ibn Ibrahim al-Balkhi (d. 809–810), for instance, regarded al-Kazim as a holy person (wali Allah, min al-abdal) and a devout worshipper, while Ma'ruf al-Kharkhi (d. c. 815) and Bishr al-Hafi (d. 841) were affiliated with the imam. In particular, a historical account credits al-Kazim with the spiritual awakening of Bishr. Musa al-Kazim is also a link in the Golden Chain (Silsilat al-dhahab), which is the initiatic line connecting the Sufis with the Islamic prophet Muhammad.

Quotations related to Musa al-Kazim at Wikiquote

Musa al-Kazim of the Ahl al-Bayt Banu Hashim Clan of the Banu Quraish Born: 7th Safar 128 AH ≈ 6 November 745 CE Died: 25th Rajab 183 AH ≈ 1 September 799 CE
Shia Islam titles
Preceded by Ja'far al-Sadiq	7th Imam of Twelver Shia Islam 765 – 799	Succeeded by Ali al-Rida