Sahih Bukhari Volume 9, Book 87, Hadith Number 147.

Narrated By Salim’s father : About the Prophet’s dream in which he has seen Abu Bakr and ‘Umar: The Prophet said, “I saw (in a dream) that the people had gathered. Then Abu Bakr stood up and pulled out one or two buckets full of water (from a well) and there was weakness in his pulling… may Allah forgive him. Then Ibn Al-Khattab stood up, and the bucket turned into a very large one and I have never seen any strong man among the people doing such a hard job. He pulled out so much water that the people (drank to their satisfaction) and watered their camels to their fill, (and then after quenching their thirst) they sat beside the water.”