Language:
كتاب التوحيد
97  
Oneness, Uniqueness of Allah (Tawheed)
(8)
Chapter: “And it is He Who has created the heavens and the earth in truth…”
(8)
Sahih al-Bukhari 7385

Narrated Ibn 'Abbas:

The Prophet (ﷺ) used to invoke Allah at night, saying, "O Allah: All the Praises are for You: You are the Lord of the Heavens and the Earth. All the Praises are for You; You are the Maintainer of the Heaven and the Earth and whatever is in them. All the Praises are for You; You are the Light of the Heavens and the Earth. Your Word is the Truth, and Your Promise is the Truth, and the Meeting with You is the Truth, and Paradise is the Truth, and the (Hell) Fire is the Truth, and the Hour is the Truth. O Allah! I surrender myself to You, and I believe in You and I depend upon You, and I repent to You and with You (Your evidences) I stand against my opponents, and to you I leave the judgment (for those who refuse my message). O Allah! Forgive me my sins that I did in the past or will do in the future, and also the sins I did in secret or in public. You are my only God (Whom I worship) and there is no other God for me (i.e. I worship none but You)."

Narrated Sufyan:

(regarding the above narration) that the Prophet (ﷺ) added, "You are the Truth, and Your Word is the Truth."

حَدَّثَنَا قَبِيصَةُ، حَدَّثَنَا سُفْيَانُ، عَنِ ابْنِ جُرَيْجٍ، عَنْ سُلَيْمَانَ، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَدْعُو مِنَ اللَّيْلِ ‏ "‏ اللَّهُمَّ لَكَ الْحَمْدُ أَنْتَ رَبُّ السَّمَوَاتِ وَالأَرْضِ، لَكَ الْحَمْدُ أَنْتَ قَيِّمُ السَّمَوَاتِ وَالأَرْضِ وَمَنْ فِيهِنَّ، لَكَ الْحَمْدُ أَنْتَ نُورُ السَّمَوَاتِ وَالأَرْضِ، قَوْلُكَ الْحَقُّ، وَوَعْدُكَ الْحَقُّ، وَلِقَاؤُكَ حَقٌّ، وَالْجَنَّةُ حَقٌّ، وَالنَّارُ حَقٌّ، وَالسَّاعَةُ حَقٌّ، اللَّهُمَّ لَكَ أَسْلَمْتُ، وَبِكَ آمَنْتُ، وَعَلَيْكَ تَوَكَّلْتُ، وَإِلَيْكَ أَنَبْتُ، وَبِكَ خَاصَمْتُ، وَإِلَيْكَ حَاكَمْتُ، فَاغْفِرْ لِي مَا قَدَّمْتُ وَمَا أَخَّرْتُ، وَأَسْرَرْتُ وَأَعْلَنْتُ، أَنْتَ إِلَهِي لاَ إِلَهَ لِي غَيْرُكَ ‏"‏‏.‏ حَدَّثَنَا ثَابِتُ بْنُ مُحَمَّدٍ حَدَّثَنَا سُفْيَانُ بِهَذَا وَقَالَ أَنْتَ الْحَقُّ وَقَوْلُكَ الْحَقُّ‏.‏
Reference : Sahih al-Bukhari 7385
In-book reference : Book 97, Hadith 15
USC-MSA web (English) reference : Vol. 9, Book 93, Hadith 482
  (deprecated numbering scheme)