Genesis 38:10

10 What he did was wicked in the sight of the LORD, so He put Onan to death as well.

Genesis 38:10 Meaning and Commentary

Genesis 38:10

And the thing which he did displeased the Lord
Being done out of envy to his brother, and through want of affection to the memory of his name; and it may be out of covetousness to get his estate into his own hands, and especially as it frustrated the end of such an usage of marrying a brother's wife; which appears to be according to the will of God, since it afterwards became a known law of his; and it was the more displeasing, as it was not only a check upon the multiplication of Abraham's seed as promised, but since the Messiah was to come from Judah. This was doing all to hinder it that lay in his power: wherefore he slew him also;
in like manner as he had slain his brother, ( Genesis 38:7 ) .

Genesis 38:10 In-Context

8 Then Judah said to Onan, “Sleep with your brother’s wife. Perform your duty as her brother-in-law and raise up offspring for your brother.”

9 But Onan knew that the offspring would not belong to him; so whenever he would sleep with his brother’s wife, he would spill his seed on the ground so that he would not produce offspring for his brother.

10 What he did was wicked in the sight of the LORD, so He put Onan to death as well.

11 Then Judah said to his daughter-in-law Tamar, “Live as a widow in your father’s house until my son Shelah grows up.” For he thought, “He may die too, like his brothers.” So Tamar went to live in her father’s house.

12 After a long time Judah’s wife, the daughter of Shua, died. When Judah had finished mourning, he and his friend Hirah the Adullamite went up to his sheepshearers at Timnah.