In biological terms, blood carries nutrients and oxygen to the cells of the bodies of animals, but it also carries symbolic significance within the context of religion. Within Christianity, the blood of Christ, a sacrificial lamb, saves sinners from eternal damnation. In the Jewish context, shed or menstrual blood is considered defiling and drinking blood is taboo. Blood is central to the Jewish covenant with God in the form of sacrifice and circumcision (Exod. 24.8). In addition to its communal bonding effect in Judaism, blood operates as a protective power as in the narrative of protecting homes from the coming plague by marking them with blood (Exod. 13.7-13), as a purifying agent for a house infected with mold, or as an application to those suffering from leprosy, likened to a mold growing on a person (Lev. 14). Among the ancient Hittites, blood is also used as a purifying agent to purify a temple or a divine image. Similar restrictions and ambiguous attitudes related to blood are evident in Islam and Hinduism.