Abdullah bin Mubarak (May Allah shower His mercy on him) says: I used to attend the circles of Abu Hanifa (May Allah be well pleased with him) day and night. Once, a discussion on menstrual rulings started and it went for 3 days, day and night. At last on the 3rd day, close to dusk, the cry of “Allahu Akbar” was raised, which signified the delight of the gathering on the conclusion of that issue. This shows that unless the hearts of the circle were enlightened, nothing was entered in the books.
One night, after Salaat Ul ‘Isha, Zufar expressed his doubts about some issue. The Imam answered him, but he wasn’t satisfied and the discussion went on so much so that it went on for the whole night. Eventually, in the morning, the issue was decided on the opinion of Imam Azam Abu Hanifa.
This shows that students had general permission to get their doubts answered. Now, it should be noted that when the Imam devoted so much time to his student out of class, then how much would he do so in the class itself? And will there be any student who will not get his doubts answered by such an affectionate teacher?
A doubt might be raised some students of Imam Azam have differed from his opinion. What is the reason for this? Muwwaffaq has answered this in Manaqib that Sahl bin Mazahim says that Abu Yusuf has differed from Imam Azam Abu Hanifa in those issues in which he didn’t understand the reason behind the Imam’s utterances. The fact was that the understanding of the Imam was very deep. Abu Yusuf himself says: In those issues in which my opinion and the opinion of the Imam was the same, I felt certain strength and radiance in my heart. In those issues, in which I differed from the Imam’s opinion, my heart would be full of weakness and doubts of the size of mountains. Khalid bin Sabeeh says: I myself have heard this from Imam Abu Yusuf.
On the face of it, the Hanafi School of Jurisprudence should follow only the opinion of Imam Abu Hanifa. Why do we need the opinion of Imam Abu Yusuf, etc.? Imam Abu Yusuf (May Allah shower His mercy on him) is one of the greatest and closest students of the Imam and he has admitted that he has no opinion of his own, but takes the opinion only. Thus, following him is like following Imam Azam only.
When Abu Yusuf (May Allah shower His mercy on him), etc. swear that all their opinions are in fact the opinions of Imam Abu Hanifa, then following them doesn’t take one out of Hanafi School of Jurisprudence.