Deuteronomy 21:15-17 Meaning: Justice for the Firstborn
15If a man has two wives, the one beloved and the other hated, and they have borne him children, both the beloved and the hated, and if the firstborn son is hers who was hated,
16then it shall be, in the day that he causes his sons to inherit that which he has, that he may not give the son of the beloved the rights of the firstborn before the son of the hated, who is the firstborn;
17but he shall acknowledge the firstborn, the son of the hated, by giving him a double portion of all that he has; for he is the beginning of his strength. The right of the firstborn is his.
15If a man have two wives, one beloved, and another hated, and they have born him children, both the beloved and the hated; and if the firstborn son be hers that was hated:
16Then it shall be, when he maketh his sons to inherit that which he hath, that he may not make the son of the beloved firstborn before the son of the hated, which is indeed the firstborn:
17But he shall acknowledge the son of the hated for the firstborn, by giving him a double portion of all that he hath: for he is the beginning of his strength; the right of the firstborn is his.
15If a man have two wives, the one beloved, and the other hated, and they have borne him children, both the beloved and the hated; and if the first-born son be hers that was hated;
16then it shall be, in the day that he causeth his sons to inherit that which he hath, that he may not make the son of the beloved the first-born before the son of the hated, who is the first-born:
17but he shall acknowledge the first-born, the son of the hated, by giving him a double portion of all that he hath; for he is the beginning of his strength; the right of the first-born is his.
15`When a man hath two wives, the one loved and the other hated, and they have borne to him sons (the loved one and the hated one), and the first-born son hath been to the hated one;
16then it hath been, in the day of his causing his sons to inherit that which he hath, he is not able to declare first-born the son of the loved one, in the face of the son of the hated one--the first-born.
17But the first-born, son of the hated one, he doth acknowledge, to give to him a double portion of all that is found with him, for he is the beginning of his strength; to him is the right of the first-born.
15If a man have two wives, one beloved, and one hated, and they have borne him children, both the beloved and the hated, and the firstborn son be hers that was hated;
16then it shall be, in the day that he maketh his sons to inherit what he hath, that he may not make the son of the beloved firstborn before the son of the hated, who is the firstborn;
17but he shall acknowledge as firstborn the son of the hated, by giving him a double portion of all that is found with him; for he is the firstfruits of his vigour: the right of the firstborn is his.
Meaning in one sentence
Why does God's law protect the firstborn son of the unloved wife? Discover how this passage guards against favoritism and upholds justice.
Context
These verses sit in a section of Deuteronomy where Moses gives laws for everyday life in Israel. Surrounding commands cover the treatment of a captive woman taken in war (verses 10-14) and the punishment of a rebellious son (verses 18-21). The passage assumes a situation that was real in the ancient world: a man with two wives, one favored and one not. Though polygamy was not God's original design (Genesis 2:24), Moses regulated it to limit its damage. Here the danger is that a father, letting his heart rule his head, would give the firstborn’s inheritance to the son of his favorite wife. So God steps in to protect the rightful place of the firstborn, no matter which mother he came from.
Key Words
Three words open up the heart of this law. First, “hated” (H8130 שָׂנֵא). In the Bible this word often means “loved less,” not despised. Jacob “hated” Leah (Genesis 29:31) in the sense that he preferred Rachel. So the “hated” wife was simply the less favored one. Already we see the law protecting someone whom the culture could easily overlook.
Second, the father is to “acknowledge” the firstborn (H5234 יַכִּיר). This verb means to recognize someone for who they truly are. The father cannot pretend the birth order is different. He must publicly honor the firstborn son’s status, even if the mother is unloved.
Third, the firstborn receives a “double portion” (פִּי שְׁנַיִם, a “mouth of two”). He inherits twice what any other son gets. This was not a new rule; it was a custom Moses strengthened. The law does not create the right of the firstborn. It defends that right from being stolen by a father’s feelings. God cares about what is already true, not just what feels convenient.
How Christians Read This Verse
Christians across traditions agree this law guards the firstborn’s inheritance against a father’s partiality. But they read the cultural setting differently. Many ancient and modern Protestant commentators (e.g., Calvin, Matthew Henry) see this as a regulation of polygamy, which Moses tolerated while limiting its injustice to children. The Jamieson-Fausset-Brown commentary, however, argues that the verb tenses in the Hebrew suggest the first wife had died, making this a law about remarriage and stepmother favoritism, not simultaneous wives. Catholic and Orthodox tradition, as reflected in the Septuagint and early church writers, likewise treats the law as a curb on paternal caprice. All agree: God’s justice protects the vulnerable, even when family structures are less than ideal.
A common misunderstanding
Some readers assume “hated” means the wife was loathed or abused, which makes God look harsh. In fact, the Hebrew word sane often simply means “loved less” (Genesis 29:31, Matthew 6:24). This law does not punish the unloved wife; it protects her son. The real target is the father’s favoritism, which could rob a child of his rightful place. God takes the side of the overlooked, not the preferred.
Living This Out
You might not have two wives, but you still have people you naturally prefer. At work, at church, in your family, it is easy to let affection shape how you treat others. This passage asks you to examine your own partiality. Are you giving someone less than they deserve because another person catches your eye? God’s law is concrete: honor what is true and just, not what feels good. This week, identify one person you may have undervalued and find a small way to treat them fairly. Let God’s justice shape your choices, not your feelings.
Main takeaway: God’s justice protects the rights of the overlooked, even when family favoritism would push them aside.
For Families
For ages 5, 8
God says dads should not just give presents to their favorite child. He wants every child to get what they deserve. He loves fairness.
For ages 9, 12
This law was written for families where a father had two wives and liked one more than the other. If the firstborn son came from the wife he liked less, the dad might want to give the bigger inheritance to his favorite son. God said no. The firstborn gets the double share, no matter which mom he has. God cares about justice, even when parents make mistakes. He always sees the one who is overlooked.
Questions People Ask
What does “hated” mean in this passage?
In Hebrew, the word often means “loved less” rather than despised. Jacob “hated” Leah in this sense. The law protects children from the effects of a parent’s favoritism.
Why does the firstborn receive a double portion?
The double portion was the traditional inheritance of the firstborn son in ancient Israel. It recognized his role as the family’s leader after the father’s death. This law makes sure he gets it regardless of which wife he came from.
Does this law mean God approves of polygamy?
No. God’s original design was one man and one woman (Genesis 2:24). This law regulates a situation Moses allowed because of human stubbornness, but it limits the injustice that can come from it.
What does “beginning of his strength” mean?
This phrase speaks of the firstborn as the first sign of a father’s virility. It emphasizes the unique honor and responsibility of the first son. That honor cannot be taken away by a father’s change of heart.
How does this law apply to Christians today?
While we no longer follow the civil laws of ancient Israel, the principle remains: God defends the vulnerable against human favoritism. It calls us to fairness, especially in family and relationships where it is easier to show partiality.
For pastors & researchers
Hebrew interlinear, 8 commentaries & word study