Musannaf Ibn Abi Shayba 13:1733

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us, from Qays ibn Muslim, from Tariq ibn Shihab: That Zayd ibn Khulaydah entered into a *salam* (forward sale) contract with ‘Atris ibn ‘Arqub for young she-camels. He asked Ibn Mas’ud about it, and he disliked *salam* in animals.