It was narrated from Sa’eed bin Jubair from Ibn 'Abbas (رضي الله عنه): (Saeed) said:

I came to him (Ibn 'Abbas) at 'Arafah and I found him eating a pomegranate. He said: Come and eat, perhaps you are fasting? The Messenger of Allah (ﷺ) did not fast it. And on one occasion he said: The Messenger of Allah (ﷺ) did not fast this day.