Musannaf Ibn Abi Shayba 35:246

Waki’ narrated to us, from Sufyan, from Abu Husayn, from a man, from Hakim ibn Hizam, that the Prophet (peace and blessings of Allah be upon him) sent him to buy a sacrificial animal for him for one dinar. He bought it, then sold it for two dinars, and brought him the one dinar. The Prophet (peace and blessings of Allah be upon him) prayed for blessing for him and ordered him to give the [other] dinar in charity. And he mentioned that Abu Hanifa said: He is liable if he sells without his permission.