Hakim ibn Hizam · Wages (Kitab Al-Ijarah)

When Abu Zur'ah made a business transaction with a man, he gave him the right of option. He then would tell him: Give me the right of option (to annul the bargain). He said: I heard AbuHurayrah say: The Messenger of Allah (ﷺ) said: Two people must separate only by mutual consent.

On his father's authority, said that his grandfather told that the Messenger of Allah (ﷺ) forbade the type of transactions in which earnest money was paid. Malik said: This means, as we think--Allah better knows-that a man buys a slave or hires an animal, and he says: I give you a dinar on condition that if I give up the transaction or hire, what I gave you is yours.