Genesis 38:6-10

⁶And Judah took a wife for Er his first-born, and her name was Tamar. ⁷And Er, Judah`s first-born, was wicked in the sight of Jehovah. And Jehovah slew him. <sup>8</sup>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. <sup>9</sup>And Onan knew that the seed would 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 he should give seed to his brother. ¹⁰And the thing which he did was evil in the sight of Jehovah: and he slew him also.