(25) باب النَّهْىِ عَنْ سَبْقِ الإِمَامِ، بِرُكُوعٍ أَوْ سُجُودٍ وَنَحْوِهِمَا
Anas reported:
The Messenger of Allah (ﷺ) one day led us in the prayer. and when he completed the Prayer he turned his face towards us and said: 0 People, I am your Imam, so do not precede me in bowing and prostration and in standing and turning (faces, i. e. In pronouncing salutation), for I see you in front of me and behind me, and then said: By Him in Whose hand Is the life of Muhammad, if you could see what I see, you would have laughed little and wept much more. They said: What did you see, Messenger of Allah? He replied: (I saw) Paradise and Hell.
Reference: Sahih Muslim 426 a
In-book reference: Book 4, Hadith 123
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 857