Musannaf Ibn Abi Shayba 13:485

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Ibn Abi Dhi’b narrated to us, from Yazid ibn ‘Abd Allah ibn Qusayt, from Abu al-Hasan al-Barrad, from ‘Ali, who said: "An animal for two animals is not permissible, nor a sheep for two sheep, except hand-to-hand (on the spot)."