Tawus says that he heard Sayyiduna Ibn Abbas (may Allah be pleased with them both) say that when the Messenger of Allah (peace and blessings be upon him) prayed tahajjud at night, he would say: 'Allahumma lakal-hamdu, anta nurus-samawati wal-ard, wa lakal-hamdu, anta qayyimus-samawati wal-ardi wa man fihinn, antal-haqq, wa wa'dukal-haqq, wa qawlukal-haqq, wa liqa'uka haqq, wal-jannatu haqq, wan-naru haqq, wan-nabiyyuna haqq. Allahumma laka aslamtu, wa bika amantu, wa 'alayka tawakkaltu, wa ilayka anabtu, wa ilayka khasamtu, wa ilayka hakamtu, faghfir li ma qaddamtu wa ma akhkhartu wa ma asrartu wa ma a'lantu, anta ilahi, la ilaha illa ant' (O Allah! Praise is for You; You are the Light of the heavens and the earth. All praise is for You alone; You manage the heavens, the earth and all that is in them. You are the Truth, and Your promise, Your word and meeting You are true; Paradise, Hell and the prophets are also true. O Allah! I submit to You, I believe in You, in You I place my trust and to You I turn in humility; to You I bring my disputes and to You I refer for judgement. Forgive me all my earlier and later sins, and forgive all the sins I have committed in secret or openly. You alone are my God; I have no god besides You).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4666