Oneness, Uniqueness of Allah (Tawheed)

Bukhari :: Book 9 :: Volume 93 :: Hadith 490

Narrated Abu Huraira:

The Prophet said, "When anyone of you goes to bed, he should dust it off thrice with the edge of his garment, and say: Bismika Rabbi wada'tu janbi, wa bika arfa'hu. In amsakta nafsi faghfir laha, wa in arsaltaha fahfazha bima tahfaz bihi 'ibadaka-s-salihin."