A Jew said to ʿUmar: "If this Verse had been revealed to us, we would have taken it as a festival (Eid): 'This day, I have perfected your religion for you.'" Umar said: "I know the day when it was revealed and the night on which it was revealed: a Friday night when we were with Messenger of Allah in Arafat."  

يَهُودِيٌّ لِعُمَرَ لَوْ عَلَيْنَا نَزَلَتْ هَذِهِ الآيَةُ لاَتَّخَذْنَاهُ عِيدًا { الْيَوْمَ أَكْمَلْتُ لَكُمْ دِينَكُمْ } قَالَ عُمَرُ قَدْ عَلِمْتُ الْيَوْمَ الَّذِي أُنْزِلَتْ فِيهِ وَاللَّيْلَةَ الَّتِي أُنْزِلَتْ لَيْلَةَ الْجُمُعَةِ وَنَحْنُ مَعَ رَسُولِ اللَّهِ ﷺ بِعَرَفَاتٍ  

"There is no day on which Allah, the Mighty and Sublime, frees more of his slaves, male and female, from the fire, than the day of Arafah. He comes close, then he boasts to the angels about them and say: 'What do these people want?'" (Sahih) Abdu Abdur-Rhamn (An-Nasai) said: It appears that Yunus bin Yusuf is the one who reported it from Malik and Allah, most High, Knows best.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَا مِنْ يَوْمٍ أَكْثَرَ مِنْ أَنْ يَعْتِقَ اللَّهُ ﷻ فِيهِ عَبْدًا أَوْ أَمَةً مِنَ النَّارِ مِنْ يَوْمِ عَرَفَةَ إِنَّهُ لَيَدْنُو ثُمَّ يُبَاهِي بِهِمُ الْمَلاَئِكَةَ وَيَقُولُ مَا أَرَادَ هَؤُلاَءِ