كتاب الأيمان والنذور
Read the English translation first, with the original Arabic directly underneath.
It was narrated that 'Abdur-Rahman bin Samurah said:
"The Prophet (ﷺ) said to me: 'If you swear an oath, and you see something that is better, then do that which is better and offer expiation for your oath.'"
إِذَا آلَيْتَ عَلَى يَمِينٍ فَرَأَيْتَ غَيْرَهَا خَيْرًا مِنْهَا فَأْتِ الَّذِي هُوَ خَيْرٌ وَكَفِّرْ عَنْ يَمِينِكَ