He therefore set about procuring weapons and forging them (1), preparing the necessary equipment, and gathering men. The deputy governor of Kūfah—al-Ḥusayn ibn Ismāʿīl—had meanwhile left the city for its outskirts, where many reinforcements sent by the caliph and by Muḥammad ibn ʿAbd Allah ibn Ṭāhir joined him; there they rested, and their horses recovered their strength (2).

On the thirteenth of Rajab, heedless advisers urged Yaḥyā ibn ʿUmar to mount, confront al-Ḥusayn ibn Ismāʿīl, and fall upon his camp. He rode out with a large force that included numerous horsemen as well as foot soldiers from the common people of Kūfah, most of them unarmed. They advanced, and when they reached the enemy (3) the latter sallied forth; a fierce battle raged in the darkness before dawn. Daybreak came only after Yaḥyā’s followers had been routed, [their ranks trampled by the cavalry, and Yaḥyā ibn ʿUmar was found] (4) after his horse had thrown him and he had been pierced in the back. They severed his head and brought it to the commander, who sent it to Muḥammad ibn ʿAbd Allah ibn Ṭāhir. The next day Muḥammad dispatched it to the caliph with a man named ʿUmar ibn al-Khaṭṭāb, brother of ʿAbd al-Raḥmān ibn al-Khaṭṭāb. The head was displayed in Sāmarrāʾ for part of the day, then it was sent (5) to Baghdad and raised near the bridge; but the crowd of onlookers (6) made that impossible, so it was placed in the arsenal instead.

When Yaḥyā’s head reached Muḥammad ibn ʿAbd Allah ibn Ṭāhir, people came to congratulate him on the victory. Abū Hāshim Dāwūd ibn al-Haytham al-Jaʿfarī entered and said, “Commander, you are being congratulated for killing a man whose death, had the Messenger of Allah ﷺ been alive, would have been mourned by him.” Muḥammad offered no reply, and Abū Hāshim withdrew, reciting (7):

O sons of Ṭāhir, gulp it down raw—
the Prophet’s flesh is hard to digest!
When Allah Himself pursues a blood-debt,
that debt, by right, will surely be paid.

The caliph al-Mustaʿīn had already sent an emir (8) to al-Ḥusayn ibn Ismāʿīl, the deputy of Kūfah. After Yaḥyā ibn ʿUmar was killed and the troops entered the city, that emir wished to put its people to the sword, but al-Ḥusayn ibn Ismāʿīl prevented him. Thus both high and low were granted safety, and Allah quenched the turmoil.