Sahih al-Bukhari 749
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · To cast a look at the Imam during As-Salat (the prayer)
Narrated Anas bin Malik:
حَدَّثَنَا مُحَمَّدُ بْنُ سِنَانٍ ، قَالَ حَدَّثَنَا فُلَيْحٌ ، قَالَ حَدَّثَنَا هِلاَلُ بْنُ عَلِيٍّ ، عَنْ أَنَسِ بْنِ مَالِكٍ ، قَالَ صَلَّى لَنَا النَّبِيُّ صلى الله عليه وسلم ثُمَّ رَقَا الْمِنْبَرَ، فَأَشَارَ بِيَدَيْهِ قِبَلَ قِبْلَةِ الْمَسْجِدِ ثُمَّ قَالَ " لَقَدْ رَأَيْتُ الآنَ مُنْذُ صَلَّيْتُ لَكُمُ الصَّلاَةَ الْجَنَّةَ وَالنَّارَ مُمَثَّلَتَيْنِ فِي قِبْلَةِ هَذَا الْجِدَارِ، فَلَمْ أَرَ كَالْيَوْمِ فِي الْخَيْرِ وَالشَّرِّ " ثَلاَثًا.
The Prophet (ﷺ) led us in prayer and then went up to the pulpit and beckoned with both hands towards the Qibla of the mosque and then said, "When I started leading you in prayer, I saw the display of Paradise and Hell on the wall of the mosque (facing the Qibla). I never saw good and bad as I have seen today." He repeated the last statement thrice.