Abu Bakr As-Siddiq had never broken his oaths till Allah revealed the expiation for the oaths. Then he said, "If I take an oath to do something and later on I find something else better than the first one, then I do what is better and make expiation for my oath." (Using translation from Bukhārī 6621)
أَبَا بَكْرٍ ؓ لَمْ يَحْنَثْ فِي يَمِينٍ قَطُّ حَتَّى أَنْزَلَ اللهُ كَفَّارَةَ الْيَمِينِ فَقَالَ لَا أَحْلِفُ عَلَى يَمِينٍ فَرَأَيْتُ غَيْرَهَا خَيْرًا مِنْهَا إِلَّا أَتَيْتُ الَّذِي هُوَ خَيْرٌ وَكَفَّرْتُ عَنْ يَمِينِي