Sahih Muslim Book 043, Hadith Number 7155.

Chapter : Not known.

Tariq b. Shihab reported that a Jew came to 'Umar and said: Commander of the Faithful, there is a verse in your Book, which you recite. Had it been revealed in connection with the Jews, we would have taken it as the day of rejoicing. Thereupon he said: Which verse do you mean? He replied: "This day I have perfected your religion for you and I have completed My favours upon you and I have chosen al-Islam as religion for you." Umar said, I know the day when it was revealed and the place where it was revealed. It was revealed to Allah's Messenger (may peace be upon him) at 'Arafat on Friday.