Sahih al-Bukhari 4606
Narrated Tariq bin Shihab:
The Jews said to `Umar, "You (i.e. Muslims) recite a Verse, and had it been revealed to us, we would 
have taken the day of its revelation as a day of celebration." `Umar said, "I know very well when and 
where it was revealed, and where Allah's Messenger (ﷺ) was when it was revealed. (It was revealed on) the 
day of `Arafat (Hajj Day), and by Allah, I was at `Arafat" Sufyan, a sub-narrator said: I am in doubt 
whether the Verse:-- "This day I have perfected your religion for you." was revealed on a Friday or 
not.
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ، حَدَّثَنَا سُفْيَانُ، عَنْ قَيْسٍ، عَنْ طَارِقِ بْنِ شِهَابٍ، قَالَتِ الْيَهُودُ لِعُمَرَ إِنَّكُمْ تَقْرَءُونَ آيَةً لَوْ نَزَلَتْ فِينَا لاَتَّخَذْنَاهَا عِيدًا‏.‏ فَقَالَ عُمَرُ إِنِّي لأَعْلَمُ حَيْثُ أُنْزِلَتْ، وَأَيْنَ أُنْزِلَتْ، وَأَيْنَ رَسُولُ اللَّهِ صلى الله عليه وسلم حِينَ أُنْزِلَتْ يَوْمَ عَرَفَةَ، وَإِنَّا وَاللَّهِ بِعَرَفَةَ ـ قَالَ سُفْيَانُ وَأَشُكُّ كَانَ يَوْمَ الْجُمُعَةِ أَمْ لاَ – ‏{‏الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ‏}‏