Musannaf Ibn Abi Shayba 29:14

Muhammad ibn Abd Allah al-Asadi narrated to us, he said: Hasan ibn Salih narrated to us, from al-Aswad ibn Qays, from his father, who said: We made a peace treaty with the people of al-Hira for one thousand dirhams and a saddle-cloth (rahl). He said: I said, "O my father, what did you used to do with the saddle-cloth?" He said: "There was no saddle-cloth for one of our companions."