It is recommended for the one who swears an oath then sees that something else is better than it; To do that which is better and offer expiation for his oath
وَحَدَّثَنَا ابْنُ أَبِي عُمَرَ، حَدَّثَنَا عَبْدُ الْوَهَّابِ الثَّقَفِيُّ، عَنْ أَيُّوبَ، عَنْ أَبِي قِلاَبَةَ، وَالْقَاسِمِ، التَّمِيمِيِّ عَنْ زَهْدَمٍ الْجَرْمِيِّ، قَالَ كَانَ بَيْنَ هَذَا الْحَىِّ مِنْ جَرْمٍ وَبَيْنَ الأَشْعَرِيِّينَ وُدٌّ وَإِخَاءٌ فَكُنَّا عِنْدَ أَبِي مُوسَى الأَشْعَرِيِّ فَقُرِّبَ إِلَيْهِ طَعَامٌ فِيهِ لَحْمُ دَجَاجٍ . فَذَكَرَ نَحْوَهُ .
This hadith has been narrated on the authority of Abu Musa al-Ash'ari with a slight variation of words.