He prayed with the Messenger of Allah during Ramadan. He bowed and said: "Subhana Rabbiyal-Azim while bowing, for as long as he had stood. Then he sat down and said: "Rabbighfirli, Rabbighfirli (Lord forgive me, Lord forgive me)," for as long as he had stood. Then he prostrated and said: "Subhana Rabbiyal-'Ala for as long as he had stood And he prayed no more than four rak'ahs when Bilal came for Al-Ghadah.
Sunan an-Nasa'i Book 20, Hadith 68