Sunan Ibn Majah
2111
Daif+3

It was narrated from 'Amr bin Shu'aib, from his father, that his grandfather said that the Prophet (ﷺ) said:"Whoever swears an oath then sees that something else is better than it, let him not do it, and his leaving it is the expiation for it

DaifAl-Albani
MunkarMuhammad Fouad Abd al-Baqi