When the governor of Medina...

When the governor of Medina, following orders, read the last will and testament, he saw that the Imam had chosen four people rather than one to administer his last will and testament: the caliph himself, the governor of Medina, 'Abdallah Aftah, the Imam's older son, and Musa, his younger son. In this way the plot of Mansur failed. The Seventh Imam Imam Musa ibn Ja'far Kazim, the son of the sixth Imam, was born in 128/744 and was poisoned and martyred in prison in 183/799.

He became Imam after the death of his father, through Divine Command and the decree of his forefathers. The seventh Imam was contemporary with the Abbasid caliphs, Mansur, Hadi, Mahdi and Harun. He lived in very difficult times, in hiding, until finally Harun went on the hajj and in Medina had the Imam arrested while praying in the Mosque of the Prophet.