It is narrated from Hazrat Hakeem bin Hizam that the Noble Prophet (peace and blessings be upon him) sent him to buy a sacrificial animal for one dinar. He bought the sacrificial animal and then sold it for two dinars. Then he bought a goat for one dinar and brought one dinar back to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) prayed for blessings for him and instructed him to give the dinar in charity. And (Imam) Abu Hanifa's opinion is mentioned that: If an agent sells (something) without the order of the principal, he will be held liable.