Mansoor bin Haashim reports:

We were once in the company of Hazrat ‘Abdullah bin Mubaarak (rahimahullah) in Qaadisiyyah when a man from Kufah came to him and began to speak ill of Imaam Abu Hanifah (rahimahullah). Hazrat ‘Abdullah bin Mubaarak (rahimahullah) reproached the man saying, “Woe to you! How can you speak ill of a man who performed ‘esha and fajr with the same wudhu for forty five years (due to spending the entire night in salaah), and he would recite the entire Qur’aan Majeed in one night in two rakaats of salaah, and I acquired the knowledge of Fiqh with which I was blessed from none other than him?”

(Tabyeedh-us-Saheefah pg. 136)