In the biblical context, the concepts of "clean" and "unclean" are deeply rooted in the laws and traditions given to the Israelites, primarily found in the Old Testament. These terms are not merely about physical cleanliness but encompass ceremonial, moral, and spiritual dimensions. The distinction between clean and unclean is a recurring theme that underscores the holiness and separateness required of God's people.

Old Testament Foundations

The primary source for understanding clean and unclean is the Mosaic Law, particularly in the books of Leviticus and Deuteronomy. Leviticus 11 provides a detailed list of animals considered clean and unclean for consumption. For example, Leviticus 11:3 states, "You may eat any animal that has a split hoof completely divided and that chews the cud." Conversely, animals that do not meet these criteria are deemed unclean.

The laws extend beyond dietary restrictions to include various aspects of daily life. Leviticus 13-15 addresses skin diseases, bodily discharges, and mildew, prescribing rituals for purification. Leviticus 15:31 emphasizes the importance of these laws: "You must keep the Israelites separate from things that make them unclean, so they will not die in their uncleanness for defiling My dwelling place, which is among them."

Ceremonial and Moral Implications

The distinction between clean and unclean also has ceremonial implications. Certain conditions rendered individuals ceremonially unclean, barring them from participating in communal worship until purification rites were completed. This separation underscores the holiness required to approach God, as seen in Leviticus 20:26 : "You are to be holy to Me because I, the LORD, am holy, and I have set you apart from the nations to be My own."

Moral and ethical behavior is also linked to the concept of cleanliness. Isaiah 1:16-17 calls for moral purity: "Wash and cleanse yourselves. Remove your evil deeds from My sight. Stop doing evil. Learn to do right; seek justice and correct the oppressor."

New Testament Perspective

In the New Testament, Jesus and the apostles address the clean and unclean laws, often challenging traditional interpretations. Jesus emphasizes the heart's condition over external observance. In Mark 7:15 , He declares, "Nothing that enters a man from the outside can defile him, but what comes out of a man, that is what defiles him."

The apostle Peter's vision in Acts 10 further illustrates the shift in understanding. In the vision, Peter is shown a sheet with various animals and is told, "Do not call anything impure that God has made clean" (Acts 10:15). This revelation signifies the inclusion of Gentiles into the faith and the abrogation of dietary restrictions.

Spiritual Significance

The clean and unclean laws serve as a metaphor for spiritual purity and the need for redemption. The sacrificial system, which provided a means for atonement and cleansing, foreshadows the ultimate sacrifice of Jesus Christ. Hebrews 9:13-14 explains, "For if the blood of goats and bulls and the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that their bodies are clean, how much more will the blood of Christ, who through the eternal Spirit offered Himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!"

The biblical narrative of clean versus unclean ultimately points to the holiness of God and the call for His people to be set apart, both in their external actions and internal dispositions.