Sahih Bukhari Volume 009, Book 092, Hadith Number 373.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 92. Holding Fast to the Qur'an and Sunnah
Narrated By Tariq bin Shihab : A Jew said to 'Umar, "O Chief of the Believers, if this verse: 'This day I have perfected your religion for you, completed My favors upon you, and have chosen for you, Islam as your religion.' (5.3) had been revealed upon us, we would have taken that day as an 'Id (festival) day." 'Umar said, "I know definitely on what day this Verse was revealed; it was revealed on the day of 'Arafat, on a Friday."