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)."
Reference: 40 Hadith Nawawi 5
English translation: Hadith 5