"When this verse was revealed 'And as for those who can fast with difficulty, (e.g. an old man), they have (a choice either to fast or) to feed a miskin (poor person) (for every day). Those among us who did not want to fast would pay the fidyah, until the verse after it was revealed and abrogated this."  

لَمَّا نَزَلَتْ هَذِهِ الآيَةُ { وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ } كَانَ مَنْ أَرَادَ مِنَّا أَنْ يُفْطِرَ وَيَفْتَدِيَ حَتَّى نَزَلَتِ الآيَةُ الَّتِي بَعْدَهَا فَنَسَخَتْهَا  

concerning this verse "And as for those who can fast with difficulty, (a choice either to fast or) to feed a Miskin (poor person) (for every day)." That for those who can fast with difficulty means they find it hard; to feed a Miskin means feeding one poor person for each day. But whoever does good of his own accord means feeding another poor person. This is not abrogated, and it is bette for him. And: that "you fast is better for you" means there is no concession regarding this except for those who are not able to fast, or who are incurably sick.  

فِي قَوْلِهِ ﷻ { وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ } يُطِيقُونَهُ يُكَلَّفُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ وَاحِدٍ { فَمَنْ تَطَوَّعَ خَيْرًا } طَعَامُ مِسْكِينٍ آخَرَ لَيْسَتْ بِمَنْسُوخَةٍ { فَهُوَ خَيْرٌ لَهُ وَأَنْ تَصُومُوا خَيْرٌ لَكُمْ } لاَ يُرَخَّصُ فِي هَذَا إِلاَّ لِلَّذِي لاَ يُطِيقُ الصِّيَامَ أَوْ مَرِيضٍ لاَ يُشْفَى