Volume 1, Book 10, Number 506:
Narrated Abu Huraira:
I heard Allah’s Apostle saying, “If there was a river at the door of anyone of you and he took a bath
in it five times a day would you notice any dirt on him?” They said, “Not a trace of dirt would be left.”
The Prophet added, “That is the example of the five prayers with which Allah blots out (annuls) evil
deeds.”