Leviticus 18:11 forbids an Israelite man from having sexual relations with a half-sister on his father’s side, meaning a daughter his father had with another woman. The verse gives the reason in its last clause: she is your sister, so the relationship is closed to you. God spoke these words through Moses to the people of Israel as they were being formed into a nation, and they are part of a longer list of family boundaries in the book of Leviticus.
“‘You shall not uncover the nakedness of your father’s wife’s daughter, conceived by your father, since she is your sister.
Leviticus 18:11 (WEB)
What Leviticus 18:11 Means
The phrase “uncover the nakedness” is the Hebrew way of speaking about sexual intimacy, not a literal instruction about clothing. The command targets a particular woman: the daughter of your father’s wife, who was born to your father. Because she shares your father, the law treats her as your sister and places her off limits in the same way a full sister would be.
The verse does not describe every possible relative or every possible situation. It names one specific relationship and states the principle behind it. A family is not only a set of individuals; it is a web of protected bonds, and God draws firm lines around intimacy to keep those bonds safe. The verse does not promise blessing for obedience in this passage, and it is not a list of penalties. It sets a boundary and explains the reason for it.
The Context of Leviticus 18:11
Leviticus is part of the Torah, the first five books of the Hebrew Bible, traditionally attributed to Moses. Chapter 18 opens with God telling Israel not to follow the practices of the Egyptians and Canaanites among whom they had lived and were about to settle. Verses 6 through 18 form a sequence of prohibitions on sexual relations within the family, moving through close relatives one by one.
Read in that sequence, verse 11 is one link in a chain that begins with a man’s mother and stepmother and ends with his sister-in-law. Seeing the pattern shows that the aim is not a random catalogue of rules but a consistent picture of what keeps a household and a community whole. That reading explains why the verse carries the word “sister” even when the person is a half-sibling: the family bond is defined by shared parentage, and the law honors it.
Key Phrases in Leviticus 18:11
Ephesians 5:3
But sexual immorality, and all uncleanness, or covetousness, let it not even be mentioned among you, as becomes saints…
(WEB)
Paul warns that sexual immorality should not even be named among believers. This pairs well with Leviticus 18:11 because it shows the same concern for purity in relationships carried into the New Testament, where holiness is expected in both thought and action.
Matthew 19:4-6
4 He answered, “Haven’t you read that he who made them from the beginning made them male and female, 5 and said, ‘For this cause a man shall leave his father and mother, and shall be joined to his wife; and the two shall become one flesh?’ 6 So that they are no more two, but one flesh. What therefore God has joined together, don’t let man tear apart.”
(WEB)
Jesus points back to the created design of marriage and family. Reading it alongside Leviticus 18:11 helps you see that God’s limits on intimacy are rooted in his original purpose for human relationships, not in arbitrary rules.
A Short Prayer From Leviticus 18:11
Lord, you made families and gave them a shape that reflects your care. Thank you for the people you have placed in my life, whether they share my blood or come to me through marriage or circumstance. Help me to honor the boundaries you have set and to protect the trust others place in me. Where my heart has wandered, bring me back to clarity and self-control. Teach me to love well within the lines you have drawn, for your glory and for the good of those around me. Amen.
