When Imaam Shaafi’ Rahmatullahi Alaihi asked Imaam Maalik Rahmtullahi Alaihi for his opinion about Imaam Abu Hanifah Rahmatullahi Alaihi, he responded:
Subhanallah! I have not seen the likes of him. By Allah! If he says that this pillar is of gold, he will be able to substantiate it with daleel (proof) from qiyaas.”
Ibnul Mubarak narrated that once Imaam Maalik said to his companions:
Verily, he (Imam Abu Hanifah Rahimahullah) has been imbued with Fiqh to the degree that there is no difficulty for him in it
Imaam Maalik Rahmatullahi Alaihi also glowingly spoke of Imaam Abu Hanifah’s Fiqh and Wara’ to Sufyaan Thauri.
Imaam Shaafi’ (Rahmatullahi Alayh) said:
Whoever contemplates tabahur (an all embracing panoptic view) on Fiqh, he is of the children of Abu Hanifah, for verily he (Imaam Abu Hanifah) has been given the taufeeq (by Allah Ta’laa) of Fiqh.”
This is according to the narration of Hurmalah. According to the narration of Ar-Rabee’, Imaam Shaafi’ said:
In Fiqh the people are the children of Abu Hanifah. I am not aware of anyone who has greater knowledge of Fiqh than him.
Imaam Shaafi’ Rahmatullah Alaihi said:
Whoever does not study his Kutub, will not acquire tabahhur in Ilm nor in Fiqh
Ibn Uyainah Rahmatullahi Alaihi said:
He was the most knowledgeable in Fiqh. I have not seen anyone more knowledgeable in Fiqh than him.
If there is a need for opinion, then it is the opinion of Maalik, Sufyaan and Abu Hanifah. Of them Abu Hanifah was most knowledgeable in Fiqh and the most sagacious.
Ibnul Mubaarak when narrating, would say:
An-Nu’maan Bin Thaabit narrated to me.” It was then said to him: “To whom are referring?” He said. “Abu Hanifah is the core of Ilm.” Some who were present, did not write this statement (in the notes they were taking from Ibnul Mubarak). Observing this, he (Ibnul Mubaarak) remained silent for a while. Then he said: “O people! How vile are your manners and your ignorance about the Aimmah! How little is your recognition of Ilm and of its Bearers! No one is more deserving than Abu Hanifah to be followed in Ilm. Know, verily, he is a Muttaqi Imaam, an Aalim of Wara’. He is a Faqeeh who has opened up knowledge which no one has hitherto opened up with profound insight, sagacity and piety.”
Then Ibnul Mubarak took an oath that he would not narrate (Hadith) to them for a month.” This was his severe reprimand for the disrespect which some had shown for Imaam Abu Hanifah (Rahmatullahi Alayh)
Imaam Thauri said to a man who said that he had come from Abu Hanifah:
You have come from one who is the most knowledgeable in Fiqh on earth.
Imaam Abu Yusuf (Rahmatullahi Alayh) said, “Ath- Thauri followed Abu Hanifah more than me”
One day while describing Imaam Abu Hanifah to Ibnul Mubaarak, he said:
Wallah! He (Abu Hanifah) held on powerfully to Ilm. He was a defender (of the Deen) especially against prohibitions. He followed the Ulama of his city. He accepted only that which was authentically narrated from Rasulullah (Sallallahu alayhi wa sallam). He had profound insight regarding the Naasikh Mansookh Ahaadith. He would search for the Ahaadith from Thiqaat (authentic narrators), and for the final acts of Rasulullah Sallalahu alayhi wa sallam). He would adopt as his Deen what he acquired from the Ulama of Kufah in following the Haqq.
Yayhya Bin Saeed Al-Qataan said:
I have not heard of any opinion more beautiful than that of Abu Hanifah
Isaa Bin Younus said
Do not believe anyone who speaks ill of him. Wallah! I have not seen anyone nobler and more knowledgeable in Fiqh than him
Yayha Bin Ma-een was asked about Imaam Abu Hanifah. He said:
He is Thiqah (reliable/authentic). I have not heard anyone saying that he is dhaeef (i.e. weak in Hadith). (Look!) this is Shu’bah who wrote to him to narrate Hadith, and he in fact, ordered him to do so. Ayoob As-Sakhtiyaani praised him, saying that he is pious and a faqeeh. Someone disparaged Imaam Abu Hanifah in the presence of Ibn Aun. The critic said that he (Abu Hanifah) would present a view, then retract it the next day.’ Ibn Aun said: ‘This is the proof for his Wara’, for verily, he retracts error and adopts rectitude. If this was not so, he would have defended his stance.
Source: Imaam A’zam Abu Hanifah Rahmatullahi Alayh by Majlisul Ulama of South Africa