from him: Abū ’l-Ṣalt and others. He was prone to confusion and error (1).

Ibn Jarīr said in his History (2): While ʿĪsā ibn Muḥammad ibn Abī Khālid was standing among his companions, a letter reached him from al-Ḥasan ibn Sahl informing him that al-Maʾmūn had appointed ʿAlī ibn Mūsā as his heir-apparent. Al-Maʾmūn, he wrote, had examined both the Abbasid line and the descendants of ʿAlī and had found no one more virtuous, more knowledgeable, or more devout than him. He therefore named him “al-Riḍā from the Family of Muḥammad,” ordered him to abandon black garments and to wear green in Ramadan of the year 201 AH, and instructed him to command those under his authority to pledge allegiance to him, to don green in their cloaks, caps, and standards, and to oblige all the people of Baghdad to do likewise.

Accordingly, ʿĪsā summoned the people of Baghdad to that pledge, offering to advance them one month’s stipend. Some refused, saying, “This is a ruse of al-Faḍl ibn Sahl.”

The Abbasid princes grew angry. Ibrāhīm and Manṣūr, the two sons of al-Mahdī, rose up, revoked their obedience, and gave the oath of allegiance to Ibrāhīm ibn al-Mahdī.

Al-Ḥākim said: al-Riḍā reached Naysābūr in the year 200 AH. Al-Maʾmūn had sent Rajāʾ ibn Abī al-Ḍaḥḥāk to bring him from Medina to Basra, then to Ahwāz; from there he travelled to Fārs, then by the Bust road to Naysābūr, having been ordered not to take the mountain route. He then proceeded with him to Marw.

Ibn Jarīr further relates: When the year 203 AH began, al-Maʾmūn set out for Ṭūs and spent several days at the grave of his father Hārūn al-Rashīd. There ʿAlī ibn Mūsā ate some grapes—and ate them in abundance.