Sahih Bukhari Volume 9, Book 87, Hadith Number 149.

Narrated By Abu Huraira : Allah’s Apostle said, “While I was sleeping, I saw myself standing over a tank (well) giving water to the people to drink. Then Abu Bakr came to me and took the bucket from me in order to relieve me and he pulled out one or two full buckets, and there was weakness in his pulling… may Allah forgive him. Then Ibn Al-Khattab took it from him and went on drawing water till the people left (after being satisfied) while the tank was over flowing with water.”