UNCLEAN, UNCLEANNESS (Heb. tūm’âh, uncleanness, defilement, niddâh, separation, impurity, ’erwâh, ’erwath dāvār, unclean things, tamē’, defiled unclean, tāmē’, to make or declare unclean, Gr. akatharsia, miasmos, pollution, akathartos, unclean, koinoō, to defile, mianō, to defile, molynō, to make filthy, spiloō, phtheirō, to corrupt). Sin arose very early in the history of mankind and brought about changes in both the physical and spiritual life of man. It has greatly affected the entire universe, making the terms “clean” and “unclean” very common in the thinking of the human race from the earliest times. These words have been factors in determining people’s diets, friends, and habits, in fact, their entire deportment. These words took on a new meaning when God began to call the nation of Israel into being. They fall largely into two main divisions: spiritual or moral uncleanness and ceremonial uncleanness.

Some have felt that there is a relation between the forbidden foods of other nations and those that the Lord forbade Israel to eat. This could be true, but it does not take away from the fact that the biblical laws on unclean foods came directly from God. All Israel’s restricted foods, unlike those of some other nations, involved the flesh of animals. Lev.11.1-Lev.11.47 is explicit in differentiating the clean from the unclean mammals (Lev.11.1-Lev.11.8, Lev.11.26-Lev.11.28), sea creatures (Lev.11.9-Lev.11.12), birds (Lev.11.13-Lev.11.25), and creeping things (Lev.11.29-Lev.11.38). Nothing that died of itself was fit for their food, nor were they to eat anything strangled. Blood was a forbidden part of their diet. Unclean for Israel were animals that did not chew the cud and part the hoof, fish that did not have both fins and scales, birds that were birds of prey or had unclean habits, and insects that did not have legs above the feet for leaping.

Certain kinds of uncleanness among the Israelites were connected with death. A dead person, regardless of the cause of death, made anyone who touched the body unclean (Num.19.22). Likewise anything the body touched (Num.19.22) or the enclosure in which the person died was made unclean (Num.19.14). Provisions were made for the cleansing of the unclean in this class by sprinkling his body with the ashes of a red heifer on the third and seventh days (Num.19.17-Num.19.19). Those who touched the carcass of an animal became unclean and could be cleansed only by washing their clothes in water (Lev.11.24-Lev.11.28). Certain types of creeping things that died made anything they touched unclean. Some objects thus touched could be cleansed by washing, whereas others had to be destroyed (Lev.11.29-Lev.11.37).

Leprosy, being a type of sin, was looked on as unclean whether it was in people, houses, or clothing. God required the person pronounced leprous by the priest to identify himself in a prescribed manner and to separate himself from the rest of the people. Any time anyone drew near to him, he was to cry “Unclean, unclean.” Since this disease was also very contagious, detailed instructions were given for dealing with it (Lev.13.1-Lev.13.59-Lev.15.1-Lev.15.33).

Whatever the seminal fluid that issued from the body touched became unclean. This applied also to certain other kinds of issues (Lev.15.1-Lev.15.18). Issues from women rendered them as well as the things they touched unclean (Lev.15.19-Lev.15.33). Regulations for the cleansing of such persons or things were carefully laid down in the two passages above. According to the law, childbirth made a woman unclean, and this uncleanness lasted for different periods of time, depending on whether the child was male or female. In this case too, special instructions were given for cleansing (Lev.13.1-Lev.13.59).

In the NT one notes the cumbersome systems of defilement developed by the scribes and Pharisees, which Jesus condemned. Most of the OT regulations passed away with the passing of the Law, and when the matter was discussed at the Jerusalem Council, only four restrictions were placed on the new believers (Acts.15.28-Acts.15.29). In the New Testament era, uncleanness has become moral, not ceremonial.