According to Encyclopedia of Islam, castration was prohibited in Islamic law "by a sort of tacit consensus" and eunuchs were acquired from Christian and Jewish traders. Al-Muqaddasi identifies a town in Spain where the operation was performed by Jews and the survivors were then sent overseas. Encyclopedia Judaica states that Talmudic law counts castration among mutilations entitling a slave to immediate release, so that the ability of Jewish slave traders to supply eunuchs to harems depended on whether they could acquire castrated males.