Musnad Ahmed: Hadith 2846

If any of you could manage not to go out on the day of al-Fitr until he eats something, let him do so. He [‘Ata’] said: I never omitted to eat before going out since I heard that from Ibn ‘Abbas (رضي الله عنه). I eat a little from the edge of the pastry or drink some milk or water. I [the narrator] said: What was the reason for that? He said: I heard him say, I think he narrated it from the Prophet (ﷺ): They did not go out until late morning, so they said: We should eat so that we will not have to hasten in our prayer.