Musnad Ahmad 25:1517

Isma'il narrated to us, Ayyub narrated to us, he said: I do not know if I heard it from Sa'id ibn Jubayr or if I was informed of it from him, he said: I came to Ibn Abbas at Arafah while he was eating a pomegranate, and he said: "The Messenger of Allah, peace and blessings of Allah be upon him, broke his fast at Arafah, and Umm al-Fadl sent milk to him, so he drank it."