The Messenger of Allah ﷺ said: Does the man who lifts his head ahead of the Imam (from prostration) not fear that Allah may change his head into the head of an ass?
مُحَمَّدٌ ﷺ أَمَا يَخْشَى الَّذِي يَرْفَعُ رَأْسَهُ قَبْلَ الإِمَامِ أَنْ يُحَوِّلَ اللَّهُ رَأْسَهُ رَأْسَ حِمَارٍ