Musannaf Ibn Abi Shayba 13:1485

Abu Bakr narrated to us, he said: Ibn al-Mubarak narrated to us, from al-Taymi, from Abu Uthman al-Nahdi, from Ibn Mas’ud, from the Prophet (peace and blessings of Allah be upon him), that he forbade meeting the caravans for trade (talaqqi al-buyu’).