"So whoever of you sights (the crescent on the first night of) the month (of Ramadan, i.e., is present at his home), he must observe Saum (fast) that month... (V.2:185)

Sahih al-Bukhari · Book 65 · Hadith 4506

حَدَّثَنَا عَيَّاشُ بْنُ الْوَلِيدِ، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّهُ قَرَأَ ‏{‏فِدْيَةٌ طَعَامُ مَسَاكِينَ‏}‏ قَالَ هِيَ مَنْسُوخَةٌ‏.‏

Narrated Nafi`: Ibn `Umar recited: "They had a choice, either fast or feed a poor for every day.." and added, "This Verse is abrogated."

Sahih al-Bukhari · Book 65 · Hadith 4507

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا بَكْرُ بْنُ مُضَرَ، عَنْ عَمْرِو بْنِ الْحَارِثِ، عَنْ بُكَيْرِ بْنِ عَبْدِ اللَّهِ، عَنْ يَزِيدَ، مَوْلَى سَلَمَةَ بْنِ الأَكْوَعِ عَنْ سَلَمَةَ، قَالَ لَمَّا نَزَلَتْ ‏{‏وَعَلَى الَّذِينَ يُطِيقُونَهُ فِدْيَةٌ طَعَامُ مِسْكِينٍ‏}‏ كَانَ مَنْ أَرَادَ أَنْ يُفْطِرَ وَيَفْتَدِيَ حَتَّى نَزَلَتِ الآيَةُ الَّتِي بَعْدَهَا فَنَس…

Narrated Salama: When the Divine Revelation: "For those who can fast, they had a choice either fast, or feed a poor for every day," (2.184) was revealed, it was permissible for one to give a ransom and give up fasting,…