Sahih Bukhari Volume 8, Book 76, Hadith Number 578.

Narated By ‘Abdullah : The Prophet said, “I am your predecessor at the Lake-Fount.” ‘Abdullah added: The Prophet said, “I am your predecessor at the Lake-Fount, and some of you will be brought in front of me till I will see them and then they will be taken away from me and I will say, ‘O Lord, my companions!’ It will be said, ‘You do not know what they did after you had left.”