Riyad as-Salihin

Abu Musa (May Allah be pleased with him) said: The Messenger of Allah (ﷺ) said, "Verily, I swear by Allah, if Allah wills, I shall not swear to do something but that if I consider something else to be better than it, then I shall make expiation for my oath and adopt the thing that is better."

[Al-Bukhari and Muslim].