Praise be to Allah.
If a person makes a mistake it should not be accepted, his mistake should be rejected, as Maalik (may Allaah have mercy on him) said: “There is no one among us whose opinion may be rejected except the occupant of this grave” meaning the Prophet (peace and blessings of Allaah be upon him). Every scholar makes mistakes and gets things right, so what he gets right is to accepted and what he gets wrong is to be ignored. If he is one of those who follow Salafi ‘aqeedah, but he makes some mistakes, the mistakes are to be rejected, but this does not put him beyond the pale of Salafi ‘aqeedah if he is known to be a follower of the salaf but he made some errors in some interpretation of hadeeth, or in some words that he spoke. The mistakes should not be accepted and he should not be followed in that. This applies to all the imams. If al-Shaafa’i or Abu Haneefah or Maalik or Ahmad or al-Thawri or al-Awzaa’i or anyone else made a mistake, what they got right should be accepted and what they got wrong should be ignored. Mistakes are anything that goes against the shar’i evidence, which is what Allaah and His Messenger said. No one will be blamed for anything except a mistake that goes against the evidence. What we must do is follow the truth. Allaah says (interpretation of the meaning):
“What Allaah gave as booty (Fay’) to His Messenger (Muhammad صلى الله عليه وسلم) from the people of the townships — it is for Allaah, His Messenger (Muhammad صلى الله عليه وسلم), the kindred (of Messenger Muhammad صلى الله عليه وسلم ), the orphans, Al‑Masaakeen (the poor), and the wayfarer, in order that it may not become a fortune used by the rich among you. And whatsoever the Messenger (Muhammad صلى الله عليه وسلم) gives you, take it; and whatsoever he forbids you, abstain (from it)”
The scholars are unanimously agreed that any person’s opinion may be taken or left except the Messenger of Allaah (peace and blessings of Allaah be upon him). What we must do is follow what he brought and accept it, and not reject anything that he brought, because of the verse quoted above and other similar verses, and because Allaah says (interpretation of the meaning):
“(And) if you differ in anything among yourselves, refer it to Allaah and His Messenger (صلى الله عليه وسل), if you believe in Allaah and in the Last Day. That is better and more suitable for final determination.”