Supplication Upon Rising for Tahajjud
Prayers to be Recited at Specific Times of the DayFrom the section 'Prayers to be Recited at Specific Times of the Day' in the book 'Prayers and Dhikr' by Mahmud Sami Ramazanoğlu - 'Prayer to be Recited Upon Rising for Tahajjud' part
It is narrated from Ibn Abbas (may Allah be pleased with him) that the Prophet (peace be upon him) would say the following when he rose for Tahajjud at night:

“Praise be to You, O Allah. You are the One who sustains all the heavens, the earth, and everything in them. Praise be to You, O my Lord! You are the Light of the heavens, the earth, and everything in them. Praise be to You, O my Lord! You are the Sovereign and Ruler of the heavens, the earth, and all that is in them. And praise be to You, for You are the Truth. Your promise is true, meeting You is true, Your word is true, Paradise is true, Hell is true, the prophets are true, Muhammad (peace and blessings be upon him) is true, and the Day of Judgment is true. I have surrendered to You, O my Lord! I have believed in You, I have trusted in You, and I have turned to You. I have struggled against the unbelievers relying on You, and in the end, I have accepted only You as the Judge. Forgive my past deeds, my future deeds, my hidden deeds, and my open deeds. You are the One Who brings forward and the One Who leaves behind. There is no god but You. Strength and power belong only to Allah.” (Bukhari, Tahajjud, 1)
