Oneness, Uniqueness of Allah (Tawheed)

Bukhari :: Book 9 :: Volume 93 :: Hadith 628

Narrated Abu Huraira:

Perhaps the Prophet mentioned the following (as Allah's Saying): "If My slave comes nearer to Me for a span, I go nearer to him for a cubit; and if he comes nearer to Me for a cubit; I go nearer to him for the span of outstretched arms. (See Hadith No. 502)