Mukhtasar Muslim (Abridged) 621 — Pilgrims should not fast on Arafah

It is narrated from Sayyida Umm Fadl bint Harith (may Allah be pleased with her) that some people came to her and differed about the fasting of the Messenger of Allah (peace and blessings be upon him) on the day of Arafah (in Arafat). Some said that he was fasting and others said that he was not. Then Umm Fadl sent a bowl of milk to the Messenger of Allah (peace and blessings be upon him), and he was staying on his camel in Arafat, so he (peace and blessings be upon him) drank it.