The Messenger of Allah ﷺ said, "Does any one of you not fear, when he raises his head while the imam is still prostrating, that Allah might transform his head into the head of a donkey, or his form into the form of a donkey?"
حدثنا حفص بن عمر حدثنا شعبة عن محمد بن زياد
قال رسول الله ﷺ أما يخشى أو ألا يخشى أحدكم إذا رفع رأسه والإمام ساجد أن يحول الله رأسه رأس حمار أو صورته صورة حمار
Muslim narrated it in Sahih Muslim, in the chapter on the prohibition of preceding the imam in bowing or prostration or the like, hadith no. 427, from the hadith of Shubah, with this chain.