Musannaf Ibn Abi Shayba 27:70

Yazid ibn Harun narrated to us, he said: Sulayman al-Taymi informed us, from Abu al-Ala’ ibn al-Shikhkhir, from Samurah ibn Jundub, that the Messenger of Allah (may Allah bless him and grant him peace) was brought a bowl of tharid. It was placed before the people, and they took turns eating from it from the morning until noon; one group would stand up and others would sit down. A man said, "O Samurah, was it being replenished?" Samurah said, "What are you amazed at? It was not being replenished except from here," and he pointed with his hand toward the sky.