Musannaf Ibn Abi Shayba 13:2523

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Ibn ‘Awn narrated to us, he said: I said to al-Qasim ibn Muhammad: "A man buys merchandise while it is absent; may he sell it before it arrives?" Al-Qasim said: "We used to say: [He should not sell it] until it arrives."