Musannaf Ibn Abi Shayba 3:5544

Ibn Idris narrated to us, from Abu ‘Asim, from ‘Ali ibn ‘Ubayd Allah, who said: Yasar ibn Numayr invited us to food at the time of Maghrib. He said: ‘Umar ibn al-Khattab used to say: "Begin with your food, then empty yourselves for your prayer."