The Messenger of Allah ﷺ said, "Whoever introduces into this matter of ours something that is not part of it, it is rejected."
قال رسول الله ﷺ: من أحدث في أمرنا هذا ما ليس فيه فهو رد.
Bukhari narrated it in "Reconciliation" (2697), and Muslim in "Judgments" (17:1718), both through the route of Ibrahim bin Saad bin Abdul-Rahman bin Awf, who said, my father narrated to us, from Qasim bin Muhammad, from Ayesha, who said what has been mentioned. The wording given is that of Bukhari, while in Muslim it reads, "that which is not part of it."