Hazrat Fudhail bin ‘Iyaadh (rahimahullah) once described Imaam Abu Hanifah (rahimahullah) in the following words:

Imaam Abu Hanifah (rahimahullah) was a Faqeeh (person blessed with the true understanding of Deen) and his mastery in the science of Fiqh (Islamic Jurisprudence) is well known to all. He was renowned for his piety, and Allah Ta‘ala had blessed him with abundant wealth. He was known for his quality of showing kindness to those who sought assistance from him. He was steadfast and committed to imparting the knowledge of deen. He would pass the night in an excellent manner through engaging in the ‘ibaadah of Allah Ta‘ala. He would remain silent and would speak very little. However, when he would be asked a mas’alah regarding halaal and haraam, then he would speak and would guide the person towards the truth in an excellent and gentle manner. He would avoid accepting any wealth or gifts from the ruler. If Imaam Abu Hanifah (rahimahullah) was asked any mas’alah regarding which there was an authentic Hadith, he would follow the Hadith and practice upon it. In the case where he did not find a Hadith, but was informed regarding the narrations of the Sahaabah and Taabi‘een, then he would follow what he received from the Sahaabah and Taabi‘een. If Imaam Abu Hanifah (rahimahullah) did not find any Hadith or narration of the Sahaabah and Taabi‘een, he would employ his ijtihaad and thereafter deduce the shar’ee ruling for the mas’alah.

(Tabyeedh-us-Saheefah pg. 123)