Musannaf Ibn Abi Shayba 13:1484

Abu Bakr narrated to us, he said: Muhammad ibn Abi ‘Adi narrated to us, from Ibn ‘Awn, from Muhammad, who said: He forbade meeting the caravans (for trade). If a man meets them and buys from them, then the owner (of the goods) has the choice (to annul the sale) when he arrives at the city.