Imām Muḥammad ibn l-Ḥasan al-Shaybānī al-Ḥanafī had many students who were masters of the Islāmic sciences in their time. Among them was one particular Imām named Abū Mūsa ‘Īsā ibn Abān ibn Ṣadaqah. ‘Īsā ibn Abān stayed in the company of Imām Muḥammad and attained proficiency in Fiqh (Jurisprudence) under his tutelage. ‘Īsā ibn Abān was appointed as the Qāḍi of Baṣrah and he held this post till his demise. ‘Īsā ibn Abān was a prolific Ḥadīth memoriser and was initially averse to the people of Fiqh.
Muḥammad ibn Samā’ah describes ‘Īsā ibn Abān as being a handsome man. He further mentions: ‘Īsā ibn Abān would offer his ṣalāh with us. I would invite him to attend the lectures of Muḥammad ibn l-Ḥasan al-Shaybāni and he would reply: “These people (ie. the students of Abū Ḥanīfah) go against Ḥadīth.” One day, ‘Īsā performed Fajr ṣalāh with us on the day of Imām Muḥammads lesson. So I (Muḥammad ibn Samā’ah) did not allow ‘Īsā ibn Abān to leave until he sat for the lecture.
I approached Imām Muḥammad after the lecture and introduced ‘Īsā ibn Abān to him. I mentioned that he is intelligent and well acquainted with Ḥadīth. However, when I encourage him to come to you he refuses and claims that we contradict Ḥadīth. Imām Muḥammad then turned towards ‘Īsā and asked, “Oh my Son! When have you seen us going against Ḥadīth? Do not assert something against us before actually hearing us out.” Thereafter, ‘Īsā enquired regarding Twenty-five categories of Ḥadīth and Imām Muḥammad answered him regarding each query, highlighting to him that which has been abrogated therein whilst producing supporting evidences. Muḥammad ibn Samā’ah mentions, after we left Imām Muḥammad, ‘Īsā ibn Abān turned to me and said: ‘There was a veil between me and the light (nūr) which has now been lifted. I could not have imagined that such a person existed. He then stayed close to Imām Muḥammad for a long period and remained under his tutelage.
(Tārikh Baghdād and al-Aṣl Li-l-Imam Muḥammad ibn-l Ḥasan al-Shaybānī)