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)

Hadith Number 4506

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Narrated Nafi`

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

Hadith Number 4507

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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, till the Verse succeeding it was revealed and abrogated it.