From Sahih Muslim (Hadith 549):
Humran, the freed slave of 'Uthman b. 'Affan, reported on the authority of 'Uthman b. 'Affan that he heard Allah's Messenger (ﷺ) say:He who performed ablution for prayer and performed it properly and then went (to observe) obligatory prayer and offered it along with people or with the congregation or in the mosque, Allah would pardon his sins
Reference: Muslim 549