Musannaf Ibn Abi Shayba 13:1487

Abu Bakr narrated to us, he said: Ubayd Allah narrated to us, from al-Rabi’ ibn Habib, from Nawfal ibn ‘Abd al-Malik, from his father, from ‘Ali, from the Prophet, may Allah bless him and grant him peace, that he forbade *al-talaqqi* (meeting the caravans outside the marketplace to buy their goods before they reach the market).