Sometime later, when Imaam Abu Hanifah (rahimahullah) had left, I said to Hazrat Sufyaan (rahimahullah), “I saw you do something today which my companions and I have not seen you doing before.” When Hazrat Sufyaan (rahimahullah) asked me what I was referring to, I replied, “When Imaam Abu Hanifah (rahimahullah) came to you, you stood up for him in such reverence and honor, made him sit in your own place and showed him immense honor and respect which we did not see you show anyone else. What was the reason for you showing him extraordinary respect?”
Hazrat Sufyaan (rahimahullah) replied, “How is it that you are surprised at the extraordinary respect that I showed to Imaam Hanifah (rahimahullah)? Do you not know that he is a man of great virtue whom Allah has blessed with an esteemed position in Deen and knowledge which very few possess? Even if I did not stand up in respect for his profound knowledge of Deen, I would still need to stand up on account of his seniority in age. (Therefore, these are two separate reasons due to which I showed him extraordinary respect and honor.) Further, if I did not stand up in honor for him due to his seniority in age, I would still need to stand up on account of his great understanding in Fiqh. Finally, even if I did not stand up in honor for his great knowledge in Fiqh, I would still need to stand up in respect for his proverbial piety and taqwa. (Hence, there are so many reasons which demand that I show him extraordinary respect and honor.)”
(Tabyeedh-us-Saheefah pg. 127)