The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1227
'A'isha reported: When the Messenger of Allah (may peace be upon him) pronounced salutation, he salutation longer than it took him to say: O Allah: Thou art Peace, and peace comes from Thee, blessed art Thou, Possessor of Glory and ]Honour; and in the narration of Ibn Numair the words are:" O Possessor of Glory and Honour."