Genesis 38:6-8

Wycliffe Bible

⁶ Soothly Judah gave a wife, that was called Tamar, to his first begotten son Er.

⁷ And Er, the first begotten son of Judah, was wayward in the sight of the Lord, and therefore he was slain of the Lord (and so the Lord killed him).

⁸ Therefore Judah said to Onan, his son, Enter thou [in] to the wife of thy brother, and be thou fellowshipped to her, that thou raise seed to thy brother. (And so Judah said to his son Onan, Sleep with thy brother’s wife, and be fellowshipped to her, and so raise thou up seed, or some sons, for thy brother.)