Musannaf Ibn Abi Shayba 13:2353

Abu Bakr narrated to us, he said: Ibn Abi Za'idah narrated to us, from Ash'ath, from Muhammad ibn Abi al-Mujalid, from Ibn Abi Awfa, he said: We used to engage in *salam* (forward sales) with the Nabataeans of the people of Ash-Sham for wheat and raisins, while the Messenger of Allah (peace and blessings of Allah be upon him) was among us.