Musnad Ahmad 340:1

'Abd al-Razzaq narrated to us, he said: Ma'mar narrated to us, from Yahya ibn Abi Kathir, from Abu Salamah ibn 'Abd al-Rahman, from Rabi'ah ibn Ka'b al-Aslami, who said: I used to sleep in the chamber of the Prophet, may Allah bless him and grant him peace. I would hear him when he stood up at night to pray, saying: "Praise be to Allah, Lord of the worlds," for a while. He said: Then he would say: "Glory be to Allah the Almighty and by His praise," for a while.