Musannaf Ibn Abi Shayba 3:3211

Ibn ‘Ulayyah narrated to us, from Yahya ibn Abi Ishaq, who said: I came to Safwan ibn Muhriz on the day of Fitr, and I sat at his door until he came out to me. He said to me, as if apologizing: "It used to be commanded on this day to consume some of one's food before going out [for the prayer], and I have consumed something, and that is what delayed me." "As for the other [person], he delays his food until he returns."