Abu Hurairahu (Radhiallahu anhu) reported:
I heard the Messenger of Allah (Sallallaahu 'alaihi wasallam) saying:
"Say, if there were a river at the door of one of you in which he takes a bath five times a day, would any soiling remain on him?'' They replied, "No soiling would left on him.'' He (Sallallaahu 'alaihi wasallam) said, '' That is the five (obligatory) Salat (prayers). Allah obliterates all sins as a result of performing them.''
[Al-Bukhari and Muslim]
I heard the Messenger of Allah (Sallallaahu 'alaihi wasallam) saying:
"Say, if there were a river at the door of one of you in which he takes a bath five times a day, would any soiling remain on him?'' They replied, "No soiling would left on him.'' He (Sallallaahu 'alaihi wasallam) said, '' That is the five (obligatory) Salat (prayers). Allah obliterates all sins as a result of performing them.''
[Al-Bukhari and Muslim]