Hadith on Hereafter: If you could see what I have seen, you would laugh little and cry more

Anas ibn Malik reported: One day the Messenger of Allah, peace and blessings be upon him, led us in prayer. He turned his face to us and said, “O people, I am your leader so do not go ahead of me in bowing, prostration, standing and turning, for I see you in front of me and behind me.” Then he said, “By him in whose hand is the soul of Muhammad, if you could see what I see then you would have laughed little and wept more.” They said, “O Messenger of Allah, what do you see?” He said, “Paradise and Hellfire.”

Source: Sahih Muslim 426

Grade: Sahih (authentic) according to Imam Muslim

عَنْ أَنَسٍ قَالَ  صَلَّى بِنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ذَاتَ يَوْمٍ فَلَمَّا قَضَى الصَّلَاةَ أَقْبَلَ عَلَيْنَا بِوَجْهِهِ فَقَالَ أَيُّهَا النَّاسُ إِنِّي إِمَامُكُمْ فَلَا تَسْبِقُونِي بِالرُّكُوعِ وَلَا بِالسُّجُودِ وَلَا بِالْقِيَامِ وَلَا بِالِانْصِرَافِ فَإِنِّي أَرَاكُمْ أَمَامِي وَمِنْ خَلْفِي ثُمَّ قَالَ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَوْ رَأَيْتُمْ مَا رَأَيْتُ لَضَحِكْتُمْ قَلِيلًا وَلَبَكَيْتُمْ كَثِيرًا قَالُوا وَمَا رَأَيْتَ يَا رَسُولَ اللَّهِ قَالَ رَأَيْتُ الْجَنَّةَ وَالنَّارَ

صحيح مسلم كتاب الصلاة باب تحريم سبق الإمام بركوع أو سجود ونحوهما 426