Is it permissible to buy a partner's share through a Murabaha to the one who commands the purchase from someone other than a bank, and is it permissible for the one commanded to purchase to refuse to sell thereafter?

It is permissible to purchase a partner's share in a company through a Murabaha to the one who commands the purchase, with an increase in price in exchange for installments, provided that the conditions of Murabaha are met. These conditions are: the availability of the conditions of sale and the absence of its impediments, the entry of the commodity into the ownership of the commanded party and the occurrence of possession, and that the responsibility for damage before delivery and its consequences after delivery fall upon the commanded party. It is permissible for the one who commands the purchase to refrain from the sale thereafter, because the binding promise resembles a sale, and for its permissibility, it is stipulated that an option (khiyar) be granted to both parties or to one of them.