Musannaf Ibn Abi Shayba 16:185

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Abu Ja’far al-Razi, from al-Rabi’, from Abu al-‘Aliyah, from Suwayd, the slave of Salman—and he praised him with good—he said: When we conquered al-Mada'in, the people went out in pursuit of the enemy. Salman said: "We have obtained a basket, so open it. If it is food, we shall eat it, and if it is wealth, we shall hand it over to these [people]." He said: So we opened it, and behold, there were loaves of fine white bread (*hawwari*), and behold, there was cheese and a knife. He said: And it was the first time the Arabs had seen fine white bread, so Salman began to describe to them how it was made. Then he took the knife and began to cut it, and he said: "In the name of Allah, eat."