Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Abu Barzah. He says: We were on one of our jihad journeys when we encountered some people from among the polytheists. So we drove them back from their campfire and we entered it, and we began to eat the (prepared) food from it. And we had heard in the days of ignorance that whoever eats this bread becomes fat. So when we ate these breads, each one of us began to look to his right and left to see whether he had become fat.