Sahih al-Bukhari 4506
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · "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)
Narrated Nafi`:
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.
Ibn `Umar recited: "They had a choice, either fast or feed a poor for every day.." and added, "This Verse is abrogated."