Mawla of the Messenger, Sayyiduna Thawban (may Allah be pleased with him) narrates that when the Messenger of Allah (peace and blessings be upon him) would finish his prayer with salam, he would seek forgiveness three times and then recite this supplication: "Allahumma anta as-salamu wa minka as-salam, tabarakta ya dhal-jalali wal-ikram." (O Allah! You are Peace and from You is peace. You are blessed, O Possessor of Majesty and Honor.)