What is the validity of endowing property held in common (Mushaa')?

Primary text

The endowment of property held in common, such as parcels of land (Suwad, plots, or shares of an orchard), is permissible. This is supported by the action of Umar, who, after receiving one hundred shares in Khaybar, sought permission from the Prophet, peace be upon him, who commanded him to endow them. Furthermore, any contract valid for an individually determined portion of a whole is valid for the jointly held portion, analogous to sales. Endowment involves dedicating the original asset and dedicating its usufruct, which is achieved in joint holdings just as it is in segregated holdings.