Sahih Muslim Book 37, Hadith Number 6621.

Chapter : The obliteration of sins with the help of seeking forgiveness from Allah.

Abu Ayyub Ansari reported that Allah’s Messenger (may peace be upon him) said: If you were not to commit sins, Allah would have swept you out of existence and would have replaced you by another people who have committed sin, and then asked forgiveness from Allah, and He would have granted them pardon.