Is it permissible to sell a commodity that is not currently owned by the seller, with the possibility of canceling the sale if the commodity does not suit the buyer?

It is not permissible to sell a commodity that the seller does not own at the time of the contract, due to the prohibition of the Prophet, peace and blessings be upon him, to Hakeem ibn Hizam against "selling what is not with him." There is no difference in this whether the buyer is compelled to buy or given a choice. It is permissible for the buyer to request the commodity without a sales contract until the seller purchases it.