But Onan knew that the offspring would not be his. So whenever he went in to his brother's wife he would waste the semen on the ground, so as not to give offspring to his brother.
Genesis 38 pauses the story of Joseph and turns to Judah's family. Verse 9 shows a man taking his brother's widow while making sure she would never bear his brother's heir. The act looks technical. Commentators look behind it to the motive, and to why the Lord answered it with death.
The Duty Onan Refused
Behind the verse stands a custom that later became law in Israel. Its aim was not private happiness but the survival of a family line and its land.
William KellyOne marked exception was needed to keep up tribal inheritance in Israel: a levirate, or brother-in-law, marriage. It existed elsewhere too, but it applied to no other people as it did to Israel, and still less to a Christian. It was used when a man died childless. His brother or next of kin then had to raise up a child for the dead man. The aim was to bind up the family line and the inheritance. This mattered so much that if the nearer kinsman refused, the widow had the right to take off his shoe in public and spit in his face.
What was at stake for the widow and the dead man was more than property.
Samuel RidoutThe law made a merciful provision: no man's family should die out while a brother was still alive to carry on the line. In Israel, to be childless was a disgrace. For a man's name to be blotted out — his family dying out — counted as a special mark of God's displeasure.
The Real Sin: Selfishness
The verse itself gives the motive: Onan knew the child would not count as his. One writer names the sin behind that, and reads verse 9 as "whenever," not "when" — a habit, not one lapse.
Edwin N. CrossOnan married Tamar but then refused to grant her the privilege of being the mother of Judah's heir. He was prepared to marry her and enjoy the relationship, but he wanted to hold back from giving of his strength. In Onan's case, the sin that is so displeasing to God was not simply spilling his seed on the ground. It was selfishness. He wanted her to stay a childless and despised widow, and that desire ruled his whole attitude. It was not a single sin but a repeated one, for the word "when" in verse 9 should read "whenever."
Another writer calls it a broken agreement.
L. M. GrantOnan, the second son, agreed to take Er's widow as his wife so as to have a child who would count as his brother's. But he did not honour his side of the agreement, and the Lord considered this serious enough to kill him too. The reason was his complete selfishness: the child would not count as his own, though in fact it would be.
God's Direct Dealing
Genesis names God in two ways, and the difference matters. One writer marks where the name "Jehovah" appears in the book.
J. N. DarbyIn the rest of the book, "Jehovah" appears in only three places. The first is Judah's case, chapter 38:7-10, where one sees His special ways and His government. The second is Joseph sold and in trial, chapter 39. The third is Jacob's waiting for His salvation. We often get "God" — His dealings as ruling all things, in contrast with men.
The Line Under Attack
This is the family through whom the Messiah would come, and the chapter opens a crisis over who will carry that line forward.
Edwin N. CrossThis passage gives us the first crisis of succession in Judah. We know that our Lord came from Judah, so we can see Satan breaking into the situation. His aim was always to hinder the coming and work of the Messiah.
One writer asks why this chapter breaks into the story of Joseph at all.
F. B. HoleIt seems the sorry story of Judah is told to bring out all the more how Joseph stood firm under a temptation of the same kind. Judah appears to have been among the better behaved of Jacob's sons. Yet the practices that marked him and his family were evil, and clearly accepted as nothing unusual.
Grace at the End of It
Onan refused to raise up his brother's line. It came anyway, and Scripture kept the record of the failure.
F. W. GrantTamar's sin was the very thing that brought her into the Lord's genealogy. And it is simply as sinners that we have the right to rejoice in a work done for sinners. In a day that is near, Judah will find his right standing not in legal righteousness, and not in mere descent from Abraham, but in the truth that God has stressed for us here.
Summary
- Duty. The custom protected two things: a dead man's name and inheritance, and his widow's hope of a child.
- Withholding. Onan took the marriage and refused the duty. Commentators put the offence in his selfishness, and in a habit he kept repeating.
- Government. The chapter uses God's covenant name, Jehovah. These deaths were His own direct dealing with Judah's line.
- Design. The Messiah would come through this line. Onan refused the very heir it needed, and Satan's hand was behind the crisis.
- Grace. The line survived. Tamar's name stands in the Lord's genealogy, sin and all, so that sinners may rejoice in a work done for sinners.