On the authority of the mother of the faithful, Aisha (ra), who said: The Messenger of Allah (ﷺ) said, “He who innovates something in this matter of ours (i.e., Islam) that is not of it will have it rejected (by Allah).” [Bukhari & Muslim] In another version in Muslim it reads: “He who does an act which we have not commanded, will have it rejected (by Allah).”

English translation · Riyad as-Salihin