Musannaf Ibn Abi Shayba 3:5548

Waki’ narrated to us, from Sharik, from Uthman al-Thaqafi, from a man who was called Ziyad, who said: We were with Ibn Abbas, and meat was being roasted for him in the oven. The prayer time arrived, so we said to him [let us go]. He said: "No, until we eat, so that it does not preoccupy us in our prayer."