Sahih Muslim , Book 4, Hadith 123 (In-Book) ⓘ

Anas reported: The Messenger of Allah 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.

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَلِيُّ بْنُ حُجْرٍ، وَاللَّفْظُ، لأَبِي بَكْرٍ قَالَ ابْنُ حُجْرٍ أَخْبَرَنَا وَقَالَ أَبُو بَكْرٍ، حَدَّثَنَا عَلِيُّ بْنُ مُسْهِرٍ، عَنِ الْمُخْتَارِ بْنِ فُلْفُلٍ، عَنْ أَنَسٍ، قَالَ صَلَّى بِنَا رَسُولُ اللَّهِ صلى الله عليه وسلم ذَاتَ يَوْمٍ فَلَمَّا قَضَى الصَّلاَةَ أَقْبَلَ عَلَيْنَا بِوَجْهِهِ فَقَالَ ‏"‏ أَيُّهَا النَّاسُ إِنِّي إِمَامُكُمْ فَلاَ تَسْبِقُونِي بِالرُّكُوعِ وَلاَ بِالسُّجُودِ وَلاَ بِالْقِيَامِ وَلاَ بِالاِنْصِرَافِ فَإِنِّي أَرَاكُمْ أَمَامِي وَمِنْ خَلْفِي - ثُمَّ قَالَ - وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَوْ رَأَيْتُمْ مَا رَأَيْتُ لَضَحِكْتُمْ قَلِيلاً وَلَبَكَيْتُمْ كَثِيرًا ‏"‏ ‏.‏ قَالُوا وَمَا رَأَيْتَ يَا رَسُولَ اللَّهِ قَالَ ‏"‏ رَأَيْتُ الْجَنَّةَ وَالنَّارَ ‏"‏ ‏.‏