Musannaf Ibn Abi Shayba 33:176

Ishaq ibn Mansur narrated to us, he said: Ja'far ibn Ziyad narrated to us, from Musa al-Juhani, from a man from Thaqif, from Anas, who said: I used to serve the Prophet, may Allah bless him and grant him peace. One day he said to me, "Do you have anything for us to eat?" I said, "Yes, O Messenger of Allah, there is some leftover food from yesterday." He said, "Did I not forbid you from keeping the food of one day for the next?"