It wasnarrated that Ibn `Abbas said:
"When the Messenger of Allah(ﷺ)prayed Tahajjud at night, he would say: "Allahumma lakal-hamd,Antanurus-samawati wal-ard wa man fihinna. Wa lakal-hamd, Antaqayyamus-samawati wal-ard wa man fihinna. Wa lakal-hamd, Antamalikus-samawati wal-ard wa man fihinna. Wa lakal-hamd, Antal-haqq,wa wa`dukahaqq, wa liqa'uka haqq, wa qawluka haqq, wal-jannatuhaqq, wan-naru haqq, was-sa`atu haqq, wan-nabiyyuna haqq, wa Muhammadun haqq. Allahumma laka aslamtu,wa bikaamantu, wa `alaika tawakkaltu wa ilaika anabtu, wa bikakhasamtu, wailaika hakamtu, faghfirli ma qaddamtu wa ma akhkhartu,wa ma asrartuwa ma a`lantu. Antal-muqaddimu wa Antal-muakhkhiru.La ilaha illa antawa la ilaha ghairuka, wa la hawla wa la quwwatailla bika (O Allah, toyou is praise, You are the Light of theheavens and the earth, andeveryone therein. To You is praise, Youare the Sustainer of theheavens and the earth, and everyone therein.To You is praise, You arethe Sovereign of the heavens and the earth,and everyone therein. ToYou is praise, You are the Truth; Yourpromise is true, the meetingwith You is true, Your saying is true,Paradise is true, the Fire istrue, the Hour is true, the Prophetsare true, and Muhammad (ﷺ) is true. OAllah, to You have I submitted, inYou I believe, in You have I put mytrust, to You I turn inrepentance, by Your help I argue, to You Irefer my case, so forgiveme for my past and future sins, what I havedone in secret and what Ihave done openly. You are the One Who bringsforward and puts back.None has the right to be worshipped but You,and there is none whohas the right to be worshipped other than You.And there is no powerand no strength except with You."Another chain that Ibn `Abbas narrated: "When the Messenger of Allah (ﷺ) stood during the night for Tahajjud," and he mentioned something similar.
English reference: Vol. 1, Book 5, Hadith 1355
Arabic reference: Book 5, Hadith 1416