Oneness, Uniqueness of Allah (Tawheed)

Bukhari :: Book 9 :: Volume 93 :: Hadith 538

Narrated Abu Huraira:

The Prophet said, "(There are) three (types of persons to whom) Allah will neither speak to them on the Day of Resurrections, nor look at them (They are):--(1) a man who takes a false oath that he has been offered for a commodity a price greater than what he has actually been offered; (2) and a man who takes a false oath after the 'Asr (prayer) in order to grab the property of a Muslim through it; (3) and a man who forbids others to use the remaining superfluous water. To such a man Allah will say on the Day of Resurrection, 'Today I withhold My Blessings from you as you withheld the superfluous part of that (water) which your hands did not create.' "