Musannaf Ibn Abi Shayba 16:296

Abu Bakr narrated to us, he said: Ibn ‘Uyaynah narrated to us, from Raja’ ibn Abi Salamah, who said: ‘Umar ibn ‘Abd al-‘Aziz used to set out food and invite people to it, but he would not eat from it, so they would not eat. He said: "What is the matter with them? They are not eating." They said: "You did not eat, so they are not eating." So he ordered a dirham every day from his own personal wealth to be spent on the cooking, and he ate, and they ate.