Oneness, Uniqueness of Allah (Tawheed)
Bukhari :: Book 9 :: Volume 93 :: Hadith 567
Narrated Abu Huraira:
Allah's Apostle said, "While I was sleeping, I saw myself (in a dream) standing by a well. I drew from it as much water as Allah wished me to draw, and then Ibn Quhafa (Abu Bakr) took the bucket from me and drew one or two buckets, and there was weakness in his drawing----may Allah forgive him! Then 'Umar took the bucket which turned into something like a big drum. I had never seen a powerful man among the people working as perfectly and vigorously as he did. (He drew so much water that) the people drank to their satisfaction and watered their camels that knelt down there. (See Hadith No. 16, Vol. 5)