Reference: Al-Fulaani in Eeqaaz al-Himam p50, tracing it to Imaam Muhammad and then saying, This does not apply to the mujtahid, for he is not bound to their views anyway, but it applies to the muqallid.
said:
When I say something contradicting the Book of Allaah سبحانه و تعالى or what is narrated from the Messenger ﷺ, then ignore my saying.
