Genesis 38:10

And the thing which he did displeased the Lord: wherefore he slew him also.

Genesis 38:10 (KJV)

Context

This verse closes the account of Judah and Tamar in Genesis 38. Judah had three sons: Er, Onan, and Shelah. Er married Tamar, but he was wicked in the Lord’s sight, so God took his life (Genesis 38:7). According to the Levirate custom, when a man died without a male heir, his brother was to marry the widow and raise offspring for the deceased brother. Judah therefore told Onan to fulfill this duty for Tamar.

Meaning

Onan refused to give his brother offspring. He deliberately prevented conception by spilling his seed on the ground. The verse says this act displeased the Lord, and God slew him also. The word “also” connects Onan’s death to Er’s earlier judgment. God saw Onan’s selfish motive and his lack of affection for his brother’s name and inheritance. His sin was not merely a private failure; it violated a God-ordained institution that later became law in Deuteronomy 25:5-10. Onan acted out of envy, wanting his brother’s estate for himself. His outward compliance hid a heart set on personal gain.

Biblical connections

This passage shows that God judges hidden motives. Onan appeared to cooperate outwardly, but his heart was selfish. The same God who judged Er and Onan later established the Levirate law to protect widows and preserve family lines. This connection helps readers see that God’s commands about marriage and family carry lasting weight. The severity of the judgment underscores the holiness of God and the certainty of His response to sin, even when it is committed in secret.

Application

God calls His people to faithfulness in every duty, especially those that involve family and covenant promises. Onan’s example warns against serving God with a divided heart. He tried to keep his brother’s inheritance while avoiding the cost. Believers today may face similar temptations to appear obedient while withholding true commitment. God sees the heart and honors those who serve Him sincerely. This account also reminds us that God defends the vulnerable, such as Tamar, and that He cares about the welfare of widows and the preservation of family lines.

Reflection

This sobering account reminds us that God is holy and just. He does not overlook sin, even when it is hidden from others. Yet His judgment also reveals His care for the vulnerable, such as Tamar. The verse calls readers to examine their own motives and to trust God’s wisdom in every area of life, including marriage and family responsibilities. It challenges us to consider whether our obedience is genuine or merely outward, and to seek a heart that delights in God’s ways.