And the thing which he did displeased the LORD; therefore He killed him also.
Genesis 38:10
Surrounding context
38:9 But Onan knew that the heir would not be his; and it came to pass, when he went in to his brother's wife, that he emitted on the ground, lest he should give an heir to his brother.
38:10 And the thing which he did displeased the LORD; therefore He killed him also.
38:11 Then Judah said to Tamar his daughter-in-law, "Remain a widow in your father's house till my son Shelah is grown." For he said, "Lest he also die like his brothers." And Tamar went and dwelt in her father's house.