The seventh commandment is five words in English and two in Hebrew.
Its brevity is deceptive.
The more carefully you unpack it, the further it reaches.
NIV “You shall not commit adultery.” (Exodus 20:14)
It began as a specific prohibition on marriage.
Jesus extended it to the condition of the heart.
And together, the commandment and its expansion describe something much larger than a rule about behavior: they describe what faithful love requires, and what its absence costs.
Five Words That Changed Everything
In Hebrew, the commandment is lo tin’af: literally “no adultery.”
There is no subject, no object, no list of qualifications.
Just a firm boundary placed around something God considered worth protecting.
The commandment was given at a moment when Israel was being formed as a nation.
Laws about faithfulness were not just personal ethics; they were the architecture of a stable society.
A community whose members could not be trusted in their most intimate commitments was a community whose other commitments would eventually collapse as well.
The Israelites received this not as a restriction but as a design: here is the shape of a life that holds together.
What Na’aph Actually Meant in Ancient Israel
The Hebrew word translated “adultery” is na’aph, and it has a specific meaning.
The Scope of the Original Word
In its original context, na’aph described a married person having sexual intercourse with someone other than their spouse.
It was not a general prohibition on sexual immorality.
It was specifically about the violation of the marriage covenant.
The Old Testament law treated this violation with extreme seriousness.
Leviticus 20:10 prescribed the death penalty for both parties, which indicates how severely the community’s structure was considered to depend on marital faithfulness.
Why the Penalty Was So Severe
Marriage in the ancient Near East was not merely a personal arrangement between two people.
It was a covenant: a solemn agreement involving the community, witnessed and binding.
Breaking it was not a private matter; it was a public betrayal of a public commitment.
The severity of the law reflected the severity of the fracture.
A community I know of lost a leader to an affair that sent reverberations through an entire organization for years.
The damage extended beyond the marriage: to trust, to governance, to confidence.
That is the social dynamic the ancient law was attempting to prevent.
What the Commandment Was Protecting
Understanding what the commandment was protecting helps explain why it mattered so much.
The Marriage Covenant
Marriage is a covenant: a binding promise made before God.
Genesis 2:24 describes the two becoming “one flesh.”
Adultery breaks that covenant from the inside.
It is not a betrayal of feelings; it is the deliberate destruction of a sacred agreement.
Hebrews 13:4 and What Marriage Is For
ESV “Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous.” (Hebrews 13:4)
The commandment against adultery is not a restriction on intimacy; it protects the context in which genuine intimacy can exist.
Proverbs on What Faithfulness Produces
NASB “Drink water from your own cistern and fresh water from your own well.” (Proverbs 5:15)
What you need is already present in the covenant you have made.
The temptation toward adultery is the belief that something better exists outside the well you already have.
What Jesus Did With This Commandment
Jesus did not abolish the seventh commandment.
He took it down to its roots.
The Sermon on the Mount Expansion
ESV “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.” (Matthew 5:27–28)
This is one of the most radical statements in the Sermon on the Mount.
Jesus is not introducing a new law; He is revealing what the commandment was always protecting.
The action is the symptom.
The lust that precedes the action is where the breach actually begins.
What This Means Practically
Jesus is not saying that attraction is sin.
He is saying that cultivating desire for what belongs to another person’s covenant is a form of unfaithfulness.
The boundary He draws is around intent, not involuntary response.
A man I heard of described a moment of clarity when a marriage counselor asked: “Are you putting as much energy into the relationship you have as the one you’re imagining?”
He said the question cracked something open.
He had been protecting the behavior while feeding the inclination.
The Standard Jesus Set
Faithfulness is not just about what you do but what you entertain.
This locates the real work in the mind and the will, before the body has done anything.
What Adultery Actually Destroys
The commandment exists because adultery causes a specific kind of damage.
What It Does to the Person Who Commits It
Paul writes in 1 Corinthians 6:18 that sexual immorality is a sin against one’s own body.
The damage to the one who breaks the covenant is personal, spiritual, and lasting.
What It Does to the Person Betrayed
A man I used to know discovered his wife’s affair through an accidentally left-open device.
He said the wound was not the act itself but the realization that he had been living inside a narrative that was not real.
Adultery not only breaks a relationship; it destabilizes the world of the person who trusted.
What It Does to the Community
Families form around marriage. Children develop within it. Communities depend on it.
When marriages are treated as disposable, the ripple effects extend far beyond two people.
The Grace That Follows the Commandment
The commandment is a prohibition.
But it does not have the last word.
What God Offers to the Broken
John 8 records the story of a woman brought to Jesus after being caught in adultery.
The crowd intended to stone her.
Jesus did not dismiss the sin; He also did not dismiss the person.
He asked her where her accusers were.
Then He said: “Go now and leave your life of sin” (John 8:11).
Grace without instruction to leave the sin would be permission.
Instruction to leave the sin without grace would be condemnation.
Jesus held both.
The Marriage That Marriage Points Toward
Ephesians 5:25–32 describes marriage as an image of Christ and the church.
Adultery against a spouse mirrors the spiritual adultery of serving other gods while claiming a covenant with God.
Faithfulness is the character of God, and the commandment calls His people to reflect that character in the most intimate human relationship.
The Seventh Commandment: What People Are Really Asking
What exactly is adultery according to the Bible?
Adultery, from the Hebrew na’aph, refers to a married person having sexual relations with someone other than their spouse. Jesus expanded the definition in Matthew 5:27–28 to include cultivating lustful intent toward another person. Both the action and the desire that precedes it constitute unfaithfulness to the marriage covenant.
Is all sexual immorality covered by the seventh commandment?
The commandment specifically addresses adultery, but biblical scholars consistently understand it as the foundation for a broader prohibition of sexual immorality. Leviticus, the New Testament, and the Westminster Shorter Catechism all extend the commandment to cover sexual sins beyond adultery, including fornication, pornography, and lust.
Is looking at someone attractive the same as committing adultery?
No. Jesus distinguishes between involuntary attraction and the cultivated intent to desire someone outside the marriage covenant. “Lustful intent” in Matthew 5:28 describes deliberate mental pursuit, not an involuntary response. The boundary is around what you choose to entertain and dwell on, not what you cannot help noticing.
Can a marriage survive adultery according to the Bible?
Jesus mentions sexual immorality as grounds for divorce in Matthew 19:9, which acknowledges the severity of the breach. However, Scripture also consistently holds out the possibility of repentance and restoration. Many marriages have survived infidelity through genuine repentance, forgiveness, and sustained rebuilding, though this requires real work from both parties.
Does the seventh commandment apply to unmarried people?
The commandment specifically addresses adultery, which involves a married person. Fornication (sexual immorality between unmarried people) is addressed separately in Scripture and is also prohibited. The seventh commandment’s broader principle of sexual faithfulness within the context of the covenant applies to all sexual ethics in the Bible.
How does Jesus’s expansion of the commandment change the standard?
It reveals that the law was always about the condition of the heart. Jesus shows the problem is not the action alone but the cultivated desire that precedes it. Faithfulness requires governing what takes root in imagination, not only what you do in the body.
For the Faithfulness This Commandment Calls For
Lord, this commandment is harder than it sounds.
Because it reaches the mind and not only the body.
It asks for faithfulness in the part of me no one else can check.
I am asking You to search that part today.
Where I have allowed imagination to go where faithfulness would not.
Where I have protected the behavior while feeding the inclination.
Give me the kind of faithfulness that is not just about what I have not done.
But about what I have chosen to honor.
Make me someone whose love is as faithful on the inside as it appears on the outside.
Amen.
Sources and Commentary Behind This Post
Wenham, G. J., & McConville, J. G. (Eds.). (1992). Exploring the Old Testament: The Pentateuch. InterVarsity Press.
Köstenberger, A. J. (2004). God, marriage, and family: Rebuilding the biblical foundation. Crossway Books.
Stuart, D. K. (2006). Exodus (New American Commentary). Broadman and Holman.
GotQuestions.org. (n.d.). What does the Bible say about adultery?
Bible Study Tools. (n.d.). Seventh commandment: You shall not commit adultery.
Crosswalk.com. (n.d.). What does “thou shalt not commit adultery” mean today?
Christianity.com. (n.d.). The seventh commandment explained: Adultery and faithfulness.
Ligonier Ministries. (n.d.). The seventh commandment. Ligonier Devotional Blog.
(2024). The Ten Commandments: Commandment 7. PastorLife Blog.
(2024). Seventh commandment: Love, not lust. Bible Teacher Blog.
(n.d.). Seventh commandment: You shall not commit adultery. Life Hope and Truth Blog.
