Thauban (RA):
Whenever Allah's Messenger (ﷺ) finished his prayer, he used to say after asking Allah's forgiveness three times: "O Allah, You are as-Salam (One Free from every defect), and as-Salam (safety from every evil) is (sought) from You. Blessed are You, O Possessor of glory and honour."
[Reported by Muslim].