Sunan an-Nasa'i 3790
سنن النسائي#3790SahihAbdur-Rahman bin Samurah said:"The Messenger of Allah said: 'If you swear an oath, then you see something that is better, then do that which is better and offer expiation for your oath
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 35:30