Imam Abu Haneefah(May Allah have mercy on him) said:
“If the hadeeth is saheeh then that is my madhhab.”
And he said: “It is not permissible for anyone to follow what we say if they do not know where we got it from.” According to another report he said: “It is haraam for the one who does not know my evidence to issue a fatwa based on my words.” And according to another report he added: “We are human, we may say something today and retract it tomorrow.” And he said: “If I say something that goes against the Book of Allaah or the report of the Messenger (peace and blessings of Allaah be upon him), then ignore what I say.”
Imam Maalik (may Allaah have mercy on him) said:
“I am only human, sometimes I make mistakes and sometimes I get things right. Look at my opinion and whatever is in accordance with the Qur’aan and Sunnah, take it, and whatever is not in accordance with the Qur’aan and Sunnah, ignore it.” And he said: “There is no one after the Prophet (peace and blessings of Allaah be upon him) whose words cannot be taken or left, apart from the Prophet (peace and blessings of Allaah be upon him).”
Imam al-Shaafa’i (may Allaah have mercy on him) said:
“There is no one who will not be unaware of some of the Sunnah of the Messenger of Allaah (peace and blessings of Allaah be upon him). Whatever I say or whatever guidelines I establish, if there is a report from the Messenger of Allaah (peace and blessings of Allaah be upon him) which is different to what I said, then what matters is what the Messenger of Allaah (peace and blessings of Allaah be upon him) said, and that is my opinion.”
Imam Ahmad(May Allah have mercy on him said:
“Do not follow me blindly and do not follow Maalik or al-Shaafa’i or al-Awzaa’i or al-Thawri blindly. Learn from where they learned.” And he said: “The opinion of al-Awzaa’i and the opinion of Maalik and the opinion of Abu Haneefah are all mere conjecture and it is all the same to me. Rather evidence is to be found in the reports – i.e., in the shar’i evidence.”
So these sayings of these Imams clearly says that we should follow what Quran and Hadiths says and if saying of any of these Imams contradicts with saying of Prophet Muhammad Saw we must not follow what Imam says but what Prophet Muhammad Saw said. May Allah Swt help us in following the Real Islam that was given by our Prophet Muhammad Saw.