Genesis 38:6-8

American Standard Version

⁶ And Judah took a wife for Er his first-born, and her name was Tamar. ⁷ And Er, Judah’s first-born, was wicked in the sight of Jehovah; and Jehovah slew him. ⁸ And Judah said unto Onan, Go in unto thy brother’s wife, and perform the duty of a husband’s brother unto her, and raise up seed to thy brother.