Sahih al-Bukhari 7268Book 96, Hadith 1
حَدَّثَنَا الْحُمَيْدِيُّ، حَدَّثَنَا سُفْيَانُ، عَنْ مِسْعَرٍ، وَغَيْرِهِ، عَنْ قَيْسِ بْنِ مُسْلِمٍ، عَنْ طَارِقِ بْنِ شِهَابٍ، قَالَ قَالَ رَجُلٌ مِنَ الْيَهُودِ لِعُمَرَ يَا أَمِيرَ الْمُؤْمِنِينَ لَوْ أَنَّ عَلَيْنَا نَزَلَتْ هَذِهِ الآيَةُ { الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ وَأَتْمَمْتُ عَلَيْكُمْ نِعْمَتِي وَرَضِيتُ لَكُمُ الإِسْلاَمَ دِينًا} لاَتَّخَذْنَا ذَلِكَ الْيَوْمَ عِيدًا. فَقَالَ عُمَرُ إِنِّي لأَعْلَمُ أَىَّ يَوْمٍ نَزَلَتْ هَذِهِ الآيَةُ، نَزَلَتْ يَوْمَ عَرَفَةَ فِي يَوْمِ جُمُعَةٍ. سَمِعَ سُفْيَانُ مِنْ مِسْعَرٍ وَمِسْعَرٌ قَيْسًا وَقَيْسٌ طَارِقًا.
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."