Genesis 38:6-10

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 unto Onan, Go in unto 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 unto his brother's wife, that he spilled it on the ground, lest that he should give seed to his brother. ¹⁰And the thing which he did displeased the LORD: wherefore he slew him also.