Sahih Bukhari Volume 1, Book 12, Hadith Number 716

Narated By Anas bin Malik : The Prophet 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.