“O Abu Ayyub, we have missed out on Jihad this year, and we were told that whoever prays in the four mosques will be forgiven his sins.” He said: “O son of my brother, shall I not tell you of something easier than that? I heard the Messenger of Allah (ﷺ) say: ‘Whoever performs ablution as he has been commanded, and prays as he has been commanded, will be forgiven his previous (bad) deeds.’” He said: “(Did he not say it) like that, O ‘Uqbah?” He said: “Yes.”
Sunan Ibn Majah Book 5, Hadith 594