"The swearing of the Messenger of Allah (ﷺ) when he took an oath and I bear witness before Allah was: 'By the One in Whose Hand is my soul."'
Sunan Ibn Majah Book 11, Hadith 2
← Previous Hadith "When the Prophet (ﷺ) took an oath he would say: 'By the One in Whose Hand is the soul of Muhammad."'

Sunan Ibn Majah Book 11, Hadith 1 Next Hadith → "The swearing most frequently sworn by the Messenger of Allah (ﷺ) was: 'No, by the Controller of the hearts."'

Sunan Ibn Majah Book 11, Hadith 3