Musannaf Ibn Abi Shayba 35:109

Ibn ‘Uyaynah narrated to us, from ‘Abdullah ibn Dinar, from Ibn ‘Umar, who said: The Messenger of Allah (ﷺ) said: "The two parties to a transaction have the option (to rescind) their sale as long as they have not separated, unless the sale was a sale of option."