The five Salat (prayers) are expiations (of sins)

Narrated Abu Huraira: I heard Allah's Messenger (ﷺ) 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 (ﷺ) added, "That is the example of the five prayers with which Allah blots out (annuls) evil deeds."