Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him), after giving the salam and before standing up, at the end of the prayer, used to say these words in a loud voice: "There is no true god except Allah, alone, without any partner; His is the dominion and His is the praise, and He has power over all things. There is no might and no power except with Allah. We worship none but Him; His is the blessing, His is the bounty, and His is the excellent praise. There is no true god except Allah; we are sincere to Him in religion, even if the disbelievers dislike it."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13907