Sayyiduna Rabi'ah bin Ka'b (may Allah be pleased with him) said: I used to spend the night with the Messenger of Allah (peace and blessings be upon him) and bring him (peace and blessings be upon him) his water for ablution and other things he needed. He (peace and blessings be upon him) would stand at night and say for a long time: "Subhana Rabbi wa bihamdih, Subhana Rabbi wa bihamdih (Glory be to my Lord and praise be to Him)," then say for a long time: "Subhana Rabbil-'alamin, Subhana Rabbil-'alamin (Glory be to the Lord of the worlds)." The Messenger of Allah (peace and blessings be upon him) said: "Do you have any need?" I said: O Messenger of Allah, your companionship in Paradise. He (peace and blessings be upon him) said: "Then help me in your own matter by prostrating much."
Hadith Referenceالمعجم الكبير للطبراني / باب الراء / 4555