That the Messenger of Allah (ﷺ) said: "Whoever swears and says: 'If Allah wills (Insha Allah), then he will not have broken it."
Jami` at-Tirmidhi Book 20, Hadith 10
← Previous Hadith That the Messenger of Allah (ﷺ) said: "Whoever swears about an oath and says: 'If Allah wills (Insha Allah), then there is no breaking of the oath against him."

Jami` at-Tirmidhi Book 20, Hadith 9 Next Hadith → From his father (Ibn 'Umar) that the Prophet (ﷺ) heard 'Umar saying: "By my father, By my father!" So he said: "Verily Allah prohibits you from swearing by your father." So 'Umar said: "By Allah I did not swear by him after that, neither intentionally nor in narrating."

Jami` at-Tirmidhi Book 20, Hadith 11