Sahih al-Bukhari 4407
Narrated Tariq bin Shibab:
Some Jews said, "Had this Verse been revealed to us, we would have taken that day as `Id (festival)." 
`Umar said, "What Verse?" They said:-- "This day I have Perfected your religion for you, Completed 
My Favor upon you And have chosen for you Islam as your religion" (5.3) `Umar said, "I know the 
place where it was revealed; It was revealed while Allah's Messenger (ﷺ) was staying at `Arafat."
حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ الثَّوْرِيُّ، عَنْ قَيْسِ بْنِ مُسْلِمٍ، عَنْ طَارِقِ بْنِ شِهَابٍ، أَنَّ أُنَاسًا، مِنَ الْيَهُودِ قَالُوا لَوْ نَزَلَتْ هَذِهِ الآيَةُ فِينَا لاَتَّخَذْنَا ذَلِكَ الْيَوْمَ عِيدًا‏.‏ فَقَالَ عُمَرُ أَيَّةُ آيَةٍ فَقَالُوا ‏{‏الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ وَأَتْمَمْتُ عَلَيْكُمْ نِعْمَتِي‏}‏‏.‏ فَقَالَ عُمَرُ إِنِّي لأَعْلَمُ أَىَّ مَكَانٍ أُنْزِلَتْ، أُنْزِلَتْ وَرَسُولُ اللَّهِ صلى الله عليه وسلم وَاقِفٌ بِعَرَفَةَ‏.‏