Is the seller permitted to keep the deposit as earnest money if the buyer backs out of the purchase?

Earnest money sale (بيع العربون) is when a portion of the price is paid at the time of the contract, and this portion goes to the seller if the buyer does not purchase the commodity. The Hanbalis permit this type of sale, unlike the majority of scholars, and the Islamic Fiqh Academy has adopted this view. If the buyer did not pay earnest money, or if what occurred was merely a promise, then the seller has no right to claim it. The sales contract is binding and cannot be revoked except with the consent of both parties. If the buyer retracts from the purchase, the sale remains binding, the commodity belongs to the buyer, and the seller demands the price from him. If the buyer delays in paying the price, the seller can revoke the contract (according to Ibn Taymiyyah), or sue the buyer, or refuse to deliver the commodity until the price is paid, or take what suffices him from the buyer's money if he comes across it.