Mishkat al-Masabih
The Excellent Qualities of the Qur'an — Hadith #2056
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " إِنَّ سُورَةً فِي الْقُرْآنِ ثَلَاثُونَ آيَةً شَفَعَتْ لِرَجُلٍ حَتَّى غُفِرَ لَهُ وَهِيَ: (تَبَارَكَ الَّذِي بِيَدِهِ الْمُلْكُ)
رَوَاهُ أَحْمَدُ وَالتِّرْمِذِيُّ وَأَبُو دَاوُدَ وَالنَّسَائِيُّ وَابْنُ مَاجَه
Abū Huraira reported God’s messenger as saying, “A sūra in the Qur’ān containing thirty verses interceded for a man till his sins were forgiven. It was ‘Blessed is He in whose hand is the kingdom.’” (Qur’ān, 67)
Ahmad, Tirmidhī, Abū Dāwūd, Nasā’i and Ibn Mājah transmitted it.