Musnad Ahmad 12:2

'Arim narrated to us, Mu'tamir ibn Sulayman narrated to us, from his father, from Abu 'Uthman, from 'Abd al-Rahman ibn Abi Bakr, that he said: We were with the Prophet, may Allah bless him and grant him peace, one hundred and thirty [men]. The Prophet, may Allah bless him and grant him peace, said: "Does any one of you have food?" It happened that a man had a *sa'* of food, or something similar. So it was kneaded. Then a disbelieving, disheveled, tall man came with sheep that he was driving. The Prophet, may Allah bless him and grant him peace, said: "Is it a sale or a gift?"—or he said: "Or a present?" He said: "No, rather a sale." So he bought a sheep from him, and it was prepared. The Prophet of Allah, may Allah bless him and grant him peace, ordered the black part of the belly to be roasted. He said: And by Allah, there was not one of the one hundred and thirty but that the Messenger of Allah, may Allah bless him and grant him peace, cut a piece from the black part of its belly for him. If he was present, he gave it to him, and if he was absent, he saved it for him. He said: And he made two large bowls from it. He said: So we all ate and were satisfied, and there remained [some] in the two bowls, so we placed it upon the camel—or as he said.