The foremost student of Imam Abu Hanifah, the mujtahid Imam, Abu Yusuf Ya’qub ibn Ibrahim, the first to be given the post of Qadi al-Qudat (Chief Judge) in Islam, would supplicate for his teacher after the obligatory Salahs, a time in which du’as are “most heard” according to a hadith recorded by al-Tirmidhi.
Hafiz Ibn ‘Abd al-Barr narrates:
‘Abd al-Warith ibn Sufyan narrated to us: He said: Qasim ibn Asbagh narrated to us: He said: Ahmad ibn Zuhayr narrated to us: He said: Sulayman ibn Abi Shaykh narrated to us: He said: Abu Sufyan al-Himyari narrated to us from ‘Ali ibn Harmalah: He said: Abu Yusuf al-Qadi used to say after his Salah: “O Allah! Forgive me, and my parents and Abu Hanifah.” (al-Intiqa’ fi Fada’il al-A’immat al-Thalathat al-Fuqaha p. 258)
The chain up to Sulayman ibn Abi Shaykh was shown to be authentic in earlier posts. Abu Sufyan al-Himyari (112 – 202), or Sa’id ibn Yahya al-Wasiti, has some narrations in Sahih al-Bukhari and Jami‘ al-Tirmidhi, and was considered reliable (saduq) by Ibn Hajar al-‘Asqalani in al-Taqrib, and trustworthy (thiqah) by Abu Dawud as mentioned in Tahdhib al-Kamal (11:109). ‘Ali ibn Harmalah, a Qadi of Kufa, was a contemporary of Imam Abu Yusuf, and is mentioned in Kitab al-Thiqat of Ibn Hibban. The chain is therefore sound.
This practice may have been inherited from Imam Abu Hanifah himself. Al-Khatib al-Baghdadi narrates with his chain that Abu Hanifah said: “I have not prayed a single Salah since Hammad [ibn Abi Sulayman] died but I sought forgiveness for him with my parents, and indeed I seek forgiveness for those from whom I acquired knowledge or [those to] whom I imparted knowledge.” (Tarikh Baghdad 15:457) The chain contains one unknown narrator, while the rest of the narrators are reliable except for Ibrahim ibn Sama’ah, the narrator from Imam Abu Hanifah, who was described as a “Shi’i” (Lisan al-Mizan 1:295).