Muwatta Malik · Hadith 1025
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَقُولُ " لاَ وَمُقَلِّبِ الْقُلُوبِ " .
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
Sahih · Salim al-Hilali