The Prophet (ﷺ) said: If anyone swears an oath and makes an exception, he may fulfil it if he wishes and break it if he wishes without any accountability for breaking.
Sunan Abi Dawud Book 22, Hadith 21
← Previous Hadith The Prophet (ﷺ) said: If anyone says when swearing an oath: "If Allah wills," he makes an exception.

Sunan Abi Dawud Book 22, Hadith 20 Next Hadith → The oath which the Messenger of Allah (ﷺ) often used was this: No, by Him who overturns the hearts.

Sunan Abi Dawud Book 22, Hadith 22