Musannaf Ibn Abi Shayba 28:391

Hassan bin Ali narrated to us, from Za'idah, from Sulayman, from Zayd bin Wahb, from Hudhayfah, who said: I passed by while the people were eating tharid (a dish of bread and broth) and meat, and Umar invited me to his food. Behold, he was eating coarse bread and oil. I said, "You prevented me from eating the tharid with the people, and you invited me to this?" He replied, "I only invited you to my food, and that (other food) is for the Muslims."