When the Prophet (ﷺ) uttered salutation at the end of the prayer, he used to say: "O Allah, forgive me my former and latter sins, what I have kept secret and what I have done openly, and what I have done extravagance; and what You know better than I do. You are the Advancer, the Delayer, there is no god but You."

Sunan Abi Dawud Book 8, Hadith 94