Sayyidah Umm al-Fadl (may Allah be pleased with her) said: The people were in doubt about fasting on the day of Arafah while we were with the Messenger of Allah (peace and blessings be upon him), so I sent a bowl of milk to him (peace and blessings be upon him) while he (peace and blessings be upon him) was at Arafah, and he (peace and blessings be upon him) drank it.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21499