مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3352
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
Ayyoob said: I do not know whether I heard it from Sa'eed bin Jubair or I was told about it from him. He said: I came to Ibn 'Abbas in 'Arafah when he was eating a pomegranate, and he said: The Messenger of Allah (ﷺ) did not fast in 'Arafah. Ummul-Fadl sent him some milk and he drank it.
Musnad Ahmad 3376A saheeh hadeeth]