The Apostle of Allah (ﷺ) said: Complete the bowing and prostration well. By Allah, I see you behind my back as to how you bow and prostrate or when you bow and prostrate.
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.
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?
The Messenger of Allah (ﷺ) came to us and said: "How is it that I see you lifting your hands like the tails of headstrong horses? Be calm in prayer." He (the narrator) said: He then again came to us and saw us (sitting) in circles. He said: "How is it that I see you in separate groups?" He (the narrator) said: He again came to us and said: "Why don't you draw yourselves up in rows as angels do in the presence of their Lord?" We said: Messenger of Allah, how do the angels draw themselves up in rows in the presence of their Lord? He (the Holy Prophet) said: "They make the first rows complete and keep close together in the row."