Sahih Muslim Book - 54, Hadith - 7527

وَحَدَّثَنِى عَبْدُ بْنُ حُمَيْدٍ أَخْبَرَنَا جَعْفَرُ بْنُ عَوْنٍ أَخْبَرَنَا أَبُو عُمَيْسٍ عَنْ قَيْسِ بْنِ مُسْلِمٍ عَنْ طَارِقِ بْنِ شِهَابٍ قَالَ جَاءَ رَجُلٌ مِنَ الْيَهُودِ إِلَى عُمَرَ فَقَالَ يَا أَمِيرَ الْمُؤْمِنِينَ آيَةٌ فِى كِتَابِكُمْ تَقْرَءُونَهَا لَوْ عَلَيْنَا نَزَلَتْ مَعْشَرَ الْيَهُودِ لاَتَّخَذْنَا ذَلِكَ الْيَوْمَ عِيدًا. قَالَ وَأَىُّ آيَةٍ قَالَ (الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ وَأَتْمَمْتُ عَلَيْكُمْ نِعْمَتِى وَرَضِيتُ لَكُمُ الإِسْلاَمَ دِينًا) فَقَالَ عُمَرُ إِنِّى لأَعْلَمُ الْيَوْمَ الَّذِى نَزَلَتْ فِيهِ وَالْمَكَانَ الَّذِى نَزَلَتْ فِيهِ نَزَلَتْ عَلَى رَسُولِ اللَّهِ -صلى الله عليه وسلم- بِعَرَفَاتٍ فِى يَوْمِ جُمُعَةٍ.

It was narrated that Tariq bin Shihab said: "A Jewish man came to 'Umar and said: 'O Commander of the believers, there is a Verse in your Book which you recite; if it had been revealed to us Jews, we would have taken that day as a (day of) festival.' He said: 'Which Verse?' He said: '...This day, I have perfected your religion for you, completed My Favor upon you, and have chosen for you Islam as your religion..." 'Umar said: 'I know the day on which it was revealed, and the place in which it was revealed. It was revealed to the Messenger of Allah (s.a.w) in 'Arafat, on a Friday."