Muwatta Malik, Book 22, Hadith 15 (USC-MSA) ⓘ
Yahya related to me from Malik that he had heard that the Messenger of Allah, may Allah bless him and grant him peace, used tosay, "No, by the Overturner of hearts."
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَقُولُ " لاَ وَمُقَلِّبِ الْقُلُوبِ " .
also referenced under: Book 22, Hadith 1028 (In-Book)