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.

UNCLEANNESS (טָמֵא, H3237, טֻמְאָה, H3240, LXX, NT ἀκάθαρτος, ἀκαθαρσία, to be unclean, unclean, uncleanness). In addition, Heb. uses various analagous terms. Since the background is always religious, NT uses κοινόω, G3124, to make common, with the force of destroying holiness, and so making or counting as unclean.

The meaning of the concept.

Persons, foods, places, and objects could all be unclean. The uncleanness could be inherent or acquired by contamination. “In the minds of the ancients there was a close connection between the notion of purity or cleanness and the notion of being consecrated to God. There was a mysterious and frightening force inherent in things which were impure and in things which were sacred, and these two forces acted on everything with which they came into contact, placing the objects or persons which touched them under a kind of interdict. Both what was impure and what was consecrated were alike ‘untouchable’” (R. de Vaux). We are dealing with concepts going back into man’s infancy, which have been modified in the OT, where there is a wide area between the holy and the impure. In the NT this has been changed. Not that which goes into a man but what comes out of him is what defiles him (Mark 7:18-20). Similarly, nothing God has made is essentially unclean (Acts 10:13-15; 1 Tim 4:4, 5).

Things that make unclean.

(a) Animals are either clean or unclean, the uncleanness being imparted by eating them or touching their dead bodies (Lev 11; Deut 14:3-20). Whatever motivations may be offered by readers for the distinction, for the Bible it lies essentially in God’s decree.

(b) All bodies which died of natural causes imparted impurity, whether the body was of a man (Num 19:11), of an impure animal (Lev 11:4-8, 24-28), or of a pure animal (11:39, 40). The killing of a pure animal for food did not render it impure, and on analogy, presumably, a man taking part in a holy war for the God of Israel would not be rendered impure by those he killed. The reason behind this is that death, the outcome of human sin, is by its very nature a negation of God’s holiness.

(c) All forbidden sexual unions rendered those partaking impure (Lev 18). Any such sexual perversions (cf. Rom 1:26, 27), are a rebellion against the God-created order of nature and therefore a stepping out of the sphere of holiness.

(d) Virtually everything linked with sex could impart uncleanness. Passages like Exodus 19:15 and 1 Samuel 21:5 show that sexual relationships were considered incompatible with divine worship. The sexual act was seen as communicating uncleanness (Lev 15:16-18), though Jewish tradition, based on v. 31, makes it refer merely to those coming into contact with anything belonging to the sanctuary. Menstruation (15:19-24), childbirth (12:1-5) and various discharges from the sexual organs (15:1-12, 25-27) created uncleanness.

(e) “Leprosy” (Lev 13), which NEB renders “a malignant skin disease,” for it is not Hansen’s disease or true leprosy, made seriously unclean. Clearly, esp. if taken with the teaching of Haggai 2:11-14, it shows that uncleanness is always stronger than holiness, and illustrates a divine command intended to impress on people how serious impurity is. No man can escape it.

Cleansing from uncleanness.

The spiritualizing of the concept.

In the prophets there is a deepening of the concept. It is expressed esp. in Isaiah’s cry, “I am a man of unclean lips” (Isa 6:5), and his confession, “We have all become like one who is unclean, and all our righteous deeds like a polluted garment” (64:6). Similarly in his picture of God’s restoration in 35:8, “The unclean shall not pass over it,” has obviously a moral rather than a ritual implication. Unfortunately in the postexilic period ever increasing stress came to be laid on the avoidance of formal uncleanness. It was an obsession both with the Qumran Covenanters and the Pharisees. In the later Talmudic developments questions of purity and impurity provide some of the most complex sections of rabbinic legislation. In the Church, however, Christ’s teaching was continued. The decisions of the apostolic gathering in Jerusalem were based on regard for those Jews who were law-bound (Acts 15:19-21). Romans 14:14 is Paul’s expression of the fact that uncleanness is something essentially spiritual in its nature (cf. Heb. 12:15). The ritual of washing has become purely pictorial, and water becomes a symbol of the word (Eph 5:26). See Clean.


J. Pedersen, Israel III-IV (1940); R. de Vaux. Ancient Israel (1958-1960, Eng. tr. 1961).

International Standard Bible Encyclopedia (1915)



1. In the Old Testament (Hebrew)

2. In the nodetitle

3. In the Septuagint



1. In the Old Testament

2. In the Apocrypha

3. In the New Testament


I. Terms.

1. In the Old Testament (Hebrew):

2. In the New Testament:

3. In the Septuagint:

Akatharsia, "uncleanness," occurs 59 times in Septuagint (including many instances in apocryphal books) (1 and 2 Esdras, Tobit, 1 and 2 Maccabees, etc.). Akathartos, "unclean," occurs 134 times in the Septuagint (including one example in 1 Maccabees). Koinos, "unclean," and koinoo, "to make unclean," occur in Esther, Proverbs, Wisdom, 1, 2, 3 and 4 Maccabees). Miaino, "to defile," occurs over 100 times. Moluno, "to make filthy," occurs 18 times (both in the Old Testament and in the Apocrypha).

II. Possible Relation of Israel’s Laws on Uncleanness with the Laws of Taboo among the Nations:

W. R. Smith (Lectures on the Religion of the Semites, 152-55) thinks there is a kinship between Israel’s laws of uncleanness and the heathen taboo. Frazer, in The Golden Bough, shows numerous examples of the taboo among various tribes and nations which present striking similarity to some of Israel’s laws on uncleanness. But does this diminish our respect for the Old Testament laws on uncleanness? Might not Yahweh use this natural religious perception of men as to an intrinsic distinction between clean and unclean in training Israel to a realization of a higher conception--the real difference between sin and holiness, i.e. between moral defilement and moral purification? The hand of Yahweh is visible even in the development of Israel’s rudimentary laws on ceremonial uncleanness. They are not explicable on purely naturalistic grounds, but Yahweh is training a people to be holy, and so He starts on the lower plane of ceremonial uncleanness and cleanness (see Le 11:44 as to the purpose of Yahweh in establishing these laws respecting clean and unclean animals).

III. Teaching as to Uncleanness.

1. In the Old Testament:

Each term above for uncleanness is used in two senses:

(a) to signify ceremonial uncleanness, which is the most usual significance of the term in the Old Testament;

(b) but, in the Prophets, to emphasize moral, rather than ceremonial, uncleanness. There are four principal spheres of uncleanness in the Old Testament:

(1) Uncleanness in the Matter of Food.

The law as to clean and unclean beasts is laid down in Le 11:1-23. Notice that the law does not extend to vegetable foods, as does a similar law in the Egyptian religion. Four kinds of beasts are named as fit for food:

(a) among quadrupeds, those that both chew the cud and part the hoof;

(b) among fishes, only those having both fins and scales;

(c) most birds or fowls, except, in the main, birds of prey and those noted for uncleanness of habits, are permitted;

(d) of insects those that have legs above the feet to leap withal (e.g. the cricket, the grasshopper, etc.), but those that go on all four, or have many feet, or go upon the belly (e.g. worms, snakes, lizards, etc.), are forbidden.

See, further, FOOD.

(2) Uncleanness Connected with the Functions of Reproduction (Leviticus 12 and 15).

In Le 15:2-18, we find the laws applied to issues of men; in 15:19 ff, to the issues of women. Not only is the man or woman unclean because of the issue, whether normal or abnormal, but the bed on which they lie, or whatever or whoever is touched by them while they are in this state, is unclean. The uncleanness lasts seven days from the cessation of the issue. To become clean men must wash their clothes and batheir bodies (though this requirement is not made of women), and both men and women must offer through the priest a pair of turtle-doves, or two young pigeons (Le 15). According to Le 13, the woman who conceives and bears a child is unclean. This uncleanness lasts seven days if the child born is a male, but 14 days if the child is a female. However, there is a partial uncleanness of the mother that continues 40 days from the birth of a male, 80 days from the birth of a female, at the end of which period she is purified by offering a lamb and a young pigeon (or turtle-dove), or if too poor to offer a lamb she may substitute one of the birds for the lamb.

(3) Uncleanness Connected with Leprosy.

According to Le 14 and 15, the leper was regarded as under the stroke of God, and so was deemed unclean. The leper (so adjudged by the priest) must separate himself from others, with torn clothes, disheveled hair, and crying with covered lips, "Unclean! Unclean!" That is, he was regarded as a dead man, and therefore unclean and so must live secluded from others.

See, further, LEPER, LEPROSY.

(4) Uncleanness Associated with Death.

According to Le 15:24-40, anyone who touched a dead beast, whether unclean or clean, was rendered unclean. According to Nu 19:11-22, anyone touching the corpse of a human being is unclean. Likewise, everyone in the tent, or who enters the tent, where lies a dead man, is unclean seven days. Even the open vessels in the tent with a dead person are unclean seven days. Whoever, furthermore, touched a dead man’s bone or grave was unclean seven days. Purification, in all these cases of uncleanness as related to death, was secured by sprinkling the ashes of a red heifer with living water upon the unclean person, or object, on the 3rd and 7th days.

See Purification.

2. In the Apocrypha:

In Tobit 3:7-9; 6:13,14; 7:11; 8:1-3; 1 Macc 1:41-53, and in other books, we find the same laws on uncleanness recognized by the descendants of Abraham. It was regarded as abominable to sacrifice other animals (swine for instance) than those prescribed by Yahweh. There is a growing sense in Israel during this period, that all customs and all conduct of the heathen are unclean. Witness the resistance of the loyal Jews to the demands of Antiochus Epiphanes (1 Macc 1; 2; 6; 7). The sense of ceremonial uncleanness was still a conspicuous element in the religious consciousness of the Jews in the inter-Biblical period. But the training of God in ceremonial purification and in the moral and spiritual teachings of the prophets had prepared the way for an advance in moral cleanness (both in thought and in practice).

3. In the New Testament:

By the days of Jesus the scribes and rabbis had wrought out a most cumbrous system of ceremonial uncleanness and purification. Nor did they claim that all their teachings on this subject were found in the Old Testament. See Tradition. This is fitly illustrated in the New Testament in the washing of hands. See Unwashen. When the Mishna (the collection of rabbinic teachings) was produced, the largest book was devoted to the laws of purification, 30 chapters being used to describe the purification of vessels alone.

See Joh 2:1-11, and note how the Jews had six stone waterpots for purification at the wedding in Cana. See Joh 3:25 as to the controversy on purification between John’s disciples and the Jews. This question of cleanness and uncleanness was a tremendous issue with every Jew. He must keep himself ceremonially clean if he would be righteous and win the approval of God.

Jesus utterly disregarded for Himself these laws of purification, though He orders the cleansed leper to return to the priest and secure his certificate of cleansing. He did not wash His hands before eating, and His disciples followed His example. Therefore, the Pharisees challenged Him to give an account of His course and that of His disciples (Mt 15:3-20 = Mr 7:6-23). Jesus then enunciated the great principle that there is no ceremonial, but only moral and spiritual, uncleanness. Not what goes into a man from hands that touch unclean things defiles the man, but the things that come out of his heart, evil thoughts, hatred, adultery, murder, etc., these defile the man.

Paul likewise regarded nothing as unclean of itself (Ro 14:14,20; Tit 1:15), yet no man should violate the scruples of his own conscience or that of his brother (and thus put a stumblingblock in his way). Love, not ceremonialism is the supreme law of the Christian. Paul, in submitting to the vow of purification in Jerusalem, set an example of this principle (Ac 21:26).



W. R. Smith, Lectures on the Religion of the Semites (especially pp. 152-55, on taboo, and pp. 455, 456, on the uncleanness of sexual intercourse); Frazer, The Golden Bough (examples of taboo and similar laws and customs among various nations); Frazer, article "Taboo" in Encyclopedia Britannica, 9th edition; Benzinger, Hebrew Archaeology; Nowack, Hebrew Archaeology; Kellogg, commentary on "Leviticus" (Expositor’s Bible); Kalisch, Leviticus; Dillmann-Ryssel, Leviticus; Schultz, Dillmann, Smend, Marti, Davidson, in their Old Testament Theologies, give useful hints on this subject; article "Casuistry" (Hebrew) in ERE, III, is valuable.

Charles B. Williams