Sunan an-Nasa'i, Book 22, Hadith 227 (In-Book) ⓘ

It was narrated that salamah bin Al-Akwa said: "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."

أَخْبَرَنَا قُتَيْبَةُ، قَالَ أَنْبَأَنَا بَكْرٌ، - وَهُوَ ابْنُ مُضَرَ - عَنْ عَمْرِو بْنِ الْحَارِثِ، عَنْ بُكَيْرٍ، عَنْ يَزِيدَ، مَوْلَى سَلَمَةَ بْنِ الأَكْوَعِ عَنْ سَلَمَةَ بْنِ الأَكْوَعِ، قَالَ لَمَّا نَزَلَتْ هَذِهِ الآيَةُ ‏{‏ وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ ‏}‏ كَانَ مَنْ أَرَادَ مِنَّا أَنْ يُفْطِرَ وَيَفْتَدِيَ حَتَّى نَزَلَتِ الآيَةُ الَّتِي بَعْدَهَا فَنَسَخَتْهَا ‏.‏