Clean and Unclean

In the Bible, “clean” and “unclean” are in the first instance cultic concepts, indicating whether something is suitable or unsuitable for use in and around the sanctuary, in particular. In later Bible books the terms also acquired a social or moral significance.

Purity Laws

Leviticus 11–15 in particular gives rules on purity. For instance, people become unclean if they touch the carcass of an animal or if they have a particular skin disease. All types of “secretions” from the sexual organs (such as menstrual blood) can make you unclean. There are also animals that must not be eaten, and even objects can be unclean, for example if they have been tainted by mould.

Cultic Significance

In the Old Testament the concepts of “clean” and “unclean” primarily apply to traditions surrounding the Temple and religious practices. When objects, people and animals are “unclean”, they cannot be used in and around the sanctuary.
Later on, the concepts acquired a related meaning and “clean” and “unclean” come to play a part in social or moral beliefs.

Holiness

In the Torah, the purity laws are primarily meant for the priests and those involved in religious rituals (Exodus 30:18-21; Numbers 8:6). According to the book of Leviticus, it is a priest’s job to differentiate between sacred and profane, and between what is ritually clean and unclean (Leviticus 10:10). The most important reason for this is the relationship between God and man. Because God is holy and represents purity, every contact with God must take place according to the rules of purity. We find this principle in what is known as the “law of holiness”, “You must keep yourselves holy, because I am holy” (Leviticus 11:44).
The command to be holy for God makes purity, first of all, a functional concept. It is a measure to assess whether someone can take part in a ritual. The distinction between clean and unclean indicates whether or not people, animals and things belong to the community and whether they may enter the sanctuary.