عَنْ عُمَيْرٍ مَوْلَى أُمِّ الْفَضْلِ أُمِّ بَنِي الْعَبَّاسِ، عَنْ أُمِّ الْفَضْلِ قَالَتْ: شَكُّوا (وَفِي لَفْظٍ تَمَارَوْا) فِي صَوْمِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَوْمَ عَرَفَةَ، فَقَالَتْ أُمُّ الْفَضْلِ: أَنَا أَعْلَمُ لَكُمْ ذَلِكَ فَبَعَثَتْ بِلَبَنٍ فَشَرِبَ
It is narrated from Sayyida Umm al-Fadl (may Allah be pleased with her), she says: The people began to doubt on the Day of Arafah whether the Noble Prophet (peace and blessings be upon him) was fasting or not. I said: I will find out for you. Then she sent milk to the Prophet (peace and blessings be upon him), which he drank.