As for ʿAlī ibn Muḥammad al-Madāʾinī, he reports on the authority of a number of transmitters who said:
Abū Muslim wrote: “To proceed: I had chosen a man as my imām and guide in fulfilling what Allah has made obligatory. He was lodged in the quarter of learning, yet he treated me as ignorant of the Qur’an and twisted it from its proper meanings for the sake of a paltry gain that Allah has already declared worthless (1) to His creation. He was like a man lured on a rope of delusion. He ordered me to bare the sword and set mercy aside, and I did so as a prelude to your rule. Then Allah delivered me through repentance. If He pardons me, pardon is what He has always been known for and ascribed with; but if He punishes me, it is for what my own hands have wrought.
“After that, he set out toward Khurāsān in defiance.”
Al-Manṣūr then instructed the Banū Hāshim who were with him to write to Abū Muslim, magnifying his standing, urging him to persevere in obedience, and encouraging him to come to al-Manṣūr.
Next al-Manṣūr said to the envoy, Abū Ḥumayd al-Marwurūdhī: “Address Abū Muslim with the gentlest words you can; promise him favors and inform him that I intend every good for him. If you despair of winning him over, then say to him:
‘By Allah, were you to plunge into the sea, I would plunge in after you; and were you to hurl yourself into the fire, I would hurl myself into it—until I kill you.’”
The envoy reached Abū Muslim at Ḥulwān.
Abū Muslim consulted his closest advisers, and they said, “Beware of him.”
When the envoy asked for an answer, Abū Muslim replied, “Return to your master; I will not come to him. I have resolved to oppose him.”
The envoy said, “Do not do that.”
Seeing that he could not persuade him, he conveyed the words al-Manṣūr had instructed. Abū Muslim fell silent for a long while, then said, “Leave.”
Those words broke his spirit and filled him with fear.
Meanwhile, al-Manṣūr had already written to Abū Dāwūd—the deputy Abū Muslim had left over Khurāsān—won him over, and said, “The governorship of Khurāsān is yours.”
So Abū Dāwūd wrote to Abū Muslim, reproaching him,