What Does Exodus 20:9 Mean?

"You shall not commit adultery." The seventh commandment's brevity matches the sixth's: two Hebrew words (lo tin'af, do not commit adultery). The prohibition's scope is the marriage covenant's protection: adultery (na'af) is sexual intercourse with another person's spouse (or, in the ancient context, a spouse engaging in sexual intercourse with someone outside the marriage).

The marriage covenant is protected by explicit divine prohibition: the sexual union that forms the "one flesh" of marriage (Genesis 2:24) is not to be violated by third-party intrusion. The commandment protects the covenant community's most basic covenantal unit, the family, by protecting its sexual-emotional foundation.

The seventh commandment's placement after the sixth (murder) and before the eighth (theft) situates the sexual covenant in the center of the commandments that protect human relationships: the human life (sixth), the marriage covenant (seventh), and the property (eighth) are the three spheres of neighbor-protection that the Decalogue's second table defends. The marriage covenant's protection is the social covenant's center: communities where marriage covenants are reliably honored are communities where children know their parents, where family commitments structure social trust, where the next generation's stability is secured.

Jesus deepens the seventh commandment as he deepens the sixth (Matthew 5:27-28): "You have heard that it was said, 'You shall not commit adultery.' But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart." The lustful gaze is the adulterous will: the desire for the prohibited relationship is already the commandment's violation in the will, not only in the act.

Paul connects the seventh commandment to the biblical theology of the body (1 Corinthians 6:18-20): the body that is "a member of Christ" and "a temple of the Holy Spirit" cannot be given to sexual immorality; the seventh commandment's bodily protection is grounded in the body's new-covenant significance as Spirit-indwelt temple.