May 22, 2020 Marc Sims

Why Did Israel Have Those Weird Purity Laws?

Why Did Israel Have Those Weird Purity Laws?

Many proposals have attempted to account for the various laws of ritual purity. Three of the most prominent may be noted. (1) These rules promoted the health of the community. In particular, the laws about unclean animals guarded the Israelites from disease carried by certain animals (e.g., pork is a carrier of trichinosis). This view has been advocated by medieval rabbis such as Rashbam and recent scholars such as R. K. Harrison. (2) These rules prevented the assimilation of foreign cultic practices into Israel’s worship of God. (3) The clean animals exhibited behaviors desirable in humans (e.g., the several references to an animal’s chewing of the cud symbolize meditating on the law). This view goes back to Jewish rabbis of the intertestamental era. An adaptation of this position in sociological categories is set forth by M. Douglas in Purity and Danger.


These explanations and others provide insight into some of the laws on ritual purity, but none of them is sufficiently encompassing. If the laws of clean/unclean animals were given to promote the people’s health, for example, Jesus did a great disservice in declaring all foods clean (Mk 7:14-20). Nevertheless, the numerous rules on washing certainly promoted the health of the ancient community, for cleanliness guards against the spread of disease. Some of these laws did set a barrier against pagan worship, but they did not do so categorically. For instance, the bull, the most valued sacrifice in Israel, was likewise highly revered by many of Israel’s neighbors. However, these rules did establish guards against occult practices, for most ceremonies dealing with demons and magic had rites that would render an Israelite unclean. Thus finding a system that accounts for these rules as a whole is formidable.


J. Milgrom has argued that the nexus of life/death is the underlying principle. This nexus does offer a wide-ranging explanation for the rules of purity/impurity. The rules dealing with a corpse or with carcasses of various animals are rooted in the abhorrence of death and in the fact that death is the opposite of holiness, the life center. Skin diseases, besides being repulsive, give the appearance of sapping the life out of person. Certainly grievous growths in bricks and garments are destructive of those materials.


The loss of blood and semen represent the loss of life-giving bodily fluids.

In light of this principle, Milgrom has posited that the laws regarding clean/unclean animals promoted reverence for life by limiting for Israel the flesh they might eat to a few animals, primarily domesticated small and large cattle, some wild game, fish, birds and locusts. His position has much to commend it. Certainly hunting as a sport did not gain the prominence in Israel that it had in Mesopotamia and Egypt. Israel’s attitude toward hunting may be rooted in the food laws and the prohibitions against consuming blood. Furthermore, many of the prohibited wild animals were carnivorous or eaters of carrion. In this light it is valid to postulate that in general the food laws were based on the death/life nexus.


These rules of clean/unclean had a powerful impact on the social and spiritual life of ancient Israel. They were a strong force for social cohesiveness. Later Jews of the Diaspora gave greater prominence to these rules in order to preserve their identity while living among Gentiles. They also provided numerous symbols of the character of holiness, especially of “unity, integrity, and perfection” (Douglas 1966, 54). The standard of wholeness explains why blemished animals could not be offered and priests with physical imperfections could not serve at the sanctuary (Lev 21:16-23; 22:17-25). The prohibition against various mixtures, such as sowing a field with two kinds of seed or wearing a garment of two different materials (Lev 19:19), symbolized the integrity of holiness. That “clean” symbolized moral purity is evidenced in the parallel of “a pure heart” with “clean hands” in Psalm 24:4.


The rules regarding corpse defilement kept the Israelites from highly valuing funerary monuments, as was the case in ancient Egypt. Since cemeteries in Israel were never considered holy ground, they could never function as places for Yahwistic worship (cf. Is 65:2-5). Burial grounds could never be located in proximity to a sanctuary, nor could a corpse be interred in a residence. These impossibilities struck a fatal blow against ancestral worship and also erected a huge barrier against occult practices, especially necromancy (cf. Deut 18:10-12). Thus they kept the concept of the demonic from enslaving the minds of God’s people.


By relegating all human *sexuality to the common area, the rules on ritual purity excluded any kind of sexual expression as a way of worshiping Yahweh. It is important to stress that these rules regarding genital discharges did not demean the proper expression of human sexuality in the marital context. They actually promoted male and female fertility, thereby enhancing the fulfillment in each family of God’s promises to Abraham that his seed would be numerous (e.g., Gen. 12:2-3). Their role was to separate this vital dimension of human living from sacred space.


The rules dealing with clean/unclean animals were a strong moral force, for they made the Israelites conscious at every meal that they were to order their lives to honor the holy God with whom they were in covenant. That this design is inherent to the food laws is confirmed by the presence of the command to be holy as God is holy. This command appears in three listings of the rules regarding edible animals (Lev 11:44-45; 20:25-26; Deut 14:21; cf. Ex 22:31). Daily observance of these food laws established a pattern of obedience to God, thereby exalting the pursuit of spiritual values above following a pragmatic way of promoting the community’s welfare.

  • J.E. Hartley in Dictionary of the Old Testament: Pentateuch, "Holy and Holiness, Clean and Unclean" InterVarsity Press.