Sahih al-Bukhari 7391
Book 97: Oneness, Uniqueness of Allah (Tawheed) · Narrated by `Abdullah
Arabic
حَدَّثَنِي سَعِيدُ بْنُ سُلَيْمَانَ، عَنِ ابْنِ الْمُبَارَكِ، عَنْ مُوسَى بْنِ عُقْبَةَ، عَنْ سَالِمٍ، عَنْ عَبْدِ اللَّهِ، قَالَ أَكْثَرُ مَا كَانَ النَّبِيُّ صلى الله عليه وسلم يَحْلِفُ " لاَ وَمُقَلِّبِ الْقُلُوبِ ".
English translation
Narrated `Abdullah:The Prophet (ﷺ) frequently used to swear, "No, by the One Who turns the hearts
Reference: Sahih al-Bukhari 7391, Book of Oneness, Uniqueness of Allah (Tawheed). English translation by Dr. Muhammad Muhsin Khan.