Genesis 38:2-10

2And Judah saw there a daughter of a certain Canaanite, whose name was Shuah; and he took her, and went in to her.

3And she conceived, and bore a son; and he called his name Er.

4And she conceived again, and bore a son; and she called his name Onan.

5And she yet again conceived, and bore a son; and called his name Shelah: and he was at Chezib, when she bore him.

6And Judah took a wife for Er his firstborn, whose name was Tamar.

7And Er, Judah’s firstborn, was wicked in the sight of the LORD; and the LORD slew him.

8And Judah said to Onan, Go in to thy brother’s wife, and marry her, and raise up seed to thy brother.

9And Onan knew that the seed should not be his; and it came to pass, when he went in to his brother’s wife, that he wasted it on the ground, lest he should give seed to his brother.

10And the thing which he did displeased the LORD: therefore he slew him also.1