If he does not accept it, it becomes binding upon the agent. It is necessary to interpret it as this scenario because he clarified it in another place, saying: 'Unless he bought it using the specific money [in hand], then the purchase is void.' He also mentioned it in the Book of Emancipation (al-Itq), and therefore it is necessary to interpret this issue according to what we have said. The purchase is only valid because he is acting upon his own liability, not with someone else's money, whether he paid the price from the principal's money or not; for the price is that which is in the liability, and what he paid is its substitute. For this reason, we said: if he purchases based on liability and pays the price for it afterward, he may use a substitute. If it turns out to be usurped, the contract is not void; rather, it is suspended upon the principal's approval because he intended the purchase for him. If he approves it, it becomes binding upon him, and he is liable for the price; if he does not accept it, it remains binding upon the one who purchased it.
Section: If he purchases using the principal's specific money, sells without his permission, purchases something for other than his principal using his specific money, or sells his property without his permission, there are two narrations [in our school]. The first: The sale is void and must be returned. This is the school of al-Shafi'i, Abu Thawr, and Ibn al-Mundhir. The second: The sale and purchase are valid and are suspended upon the owner's approval. If he approves it, it takes effect and the sale becomes binding; if he does not approve it, it is void. This is the school of Malik, Ishaq, and the opinion of Abu Hanifa regarding the sale. As for the purchase, he maintains it always occurs for the purchaser [the agent]. The basis for this second narration is what Urwa ibn al-Ja'd al-Bariqi (may God be pleased with him) narrated: that the Prophet (peace and blessings of God be upon him) gave him a dinar to buy a sheep for him. He bought two sheep, then sold one of them for a dinar on the way back. He said: 'I came to the Prophet (peace and blessings of God be upon him) with the dinar and the sheep and informed him.' He said: 'May God bless the transaction of your right hand.' Narrated by al-Athram and Ibn Majah. Also, it is a contract that has someone to authorize it at the time of its occurrence, so it must be suspended upon his approval, like a will. The basis for the first narration is the statement of the Prophet (peace and blessings of God be upon him) to Hakim ibn Hizam: 'Do not sell what you do not possess.'
(1) Reported by Ibn Majah, in: The Chapter of the Trustee Trading with Wealth and Making a Profit, from the Book of Charity (al-Sadaqat). Sunan Ibn Majah 2/803. It was also reported by al-Bukhari, in: The Chapter 'Muhammad ibn al-Muthanna related to me...', from the Book of Merits (al-Manaqib). Sahih al-Bukhari 4/252; and Abu Dawud, in: The Chapter 'On the Mudharib (investor) who violates instructions', from the Book of Sales (al-Buyu'). Sunan Abi Dawud 2/229; and al-Tirmidhi, in: The Chapter 'Abu Kurayb related to me...', from the Chapters of Sales. Aridat al-Ahwadhi 5/263; and Imam Ahmad, in: al-Musnad 4/376.