In that same year Abu al-Saraya’s brother rose in rebellion at Kufah (1). He unfurled the white banners (2), whereupon Ibrahim ibn al-Mahdi sent troops against him; the rebel was slain and his head was carried to Ibrahim.
On the night of the fourteenth of Rabiʿ al-Akhar that year, a red glow appeared in the sky, then vanished; two crimson columns remained in the heavens until the end of the night. Fierce battles were then fought in Kufah between the partisans of Ibrahim and those of al-Maʾmun. Ibrahim’s men wore black, al-Maʾmun’s wore green, and the fighting lasted until the closing days of Rajab.
That year Ibrahim ibn al-Mahdi also captured Sahl ibn Salamah al-Mutawwiʿi and imprisoned him. A band of people had gathered around Sahl to “command the right and forbid the wrong,” but they (3) exceeded all bounds: they censured the ruler, called for rule by the Book and the Sunnah, and turned the gate of Sahl’s house into something resembling a prince’s portal, complete with weapons, guards, and other trappings of kingship. The troops attacked, routed his followers, and he threw down his arms, hiding among the women and onlookers. He then slipped into one of the alleyways, was seized, and brought to Ibrahim, who kept him in prison for an entire year.
During that same year al-Maʾmun set out from Khurasan toward Iraq. ʿAli ibn Musa ibn Jaʿfar, the ʿAlid, had informed him of the turmoil and dissension there: that the Hashimites were accusing al-Maʾmun of being bewitched and insane (4); that they might resent his having pledged the succession to ʿAli; and that war was raging between al-Hasan ibn Sahl and Ibrahim ibn al-Mahdi. Al-Maʾmun therefore summoned a group of his commanders and relatives (5) and questioned them about what ʿAli al-Riḍa had reported (6). After receiving a guarantee of safety, they confirmed the matter and said to him:
“Al-Fadl ibn Sahl was the one who urged you to kill Harthamah (7), though he had been loyal to you; deal with him swiftly. As for Ṭahir ibn al-Husayn, he smoothed affairs for you until he brought…"