"The Prophet broke (the fast) of Arafah, Umm Fadl sent him some milk to drink."  

أَنَّ النَّبِيَّ ﷺ أَفْطَرَ بِعَرَفَةَ وَأَرْسَلَتْ إِلَيْهِ أُمُّ الْفَضْلِ بِلَبَنٍ فَشَرِبَ وَفِي الْبَابِ عَنْ أَبِي هُرَيْرَةَ وَابْنِ عُمَرَ وَأُمِّ الْفَضْلِ  

"Ibn Umar was asked about fasting (the Day of) Arafah (at Arafat). He said: 'I performed Hajj with the Prophet, and he did not fast it, and with Abu Bakr, and he did not fast it, and with Umar, and he did not fast it, and with Uthman, and he did not fast it. I do no fast it, nor order it nor forbid it."  

حَجَجْتُ مَعَ النَّبِيِّ ﷺ فَلَمْ يَصُمْهُ وَمَعَ أَبِي بَكْرٍ فَلَمْ يَصُمْهُ وَمَعَ عُمَرَ فَلَمْ يَصُمْهُ وَمَعَ عُثْمَانَ فَلَمْ يَصُمْهُ وَأَنَا لاَ أَصُومُهُ وَلاَ آمُرُ بِهِ وَلاَ أَنْهَى عَنْهُ