Gen.38: And she conceived again, and bare a son; and she called his name Onan.
Gen.38: And Judah said unto Onan, Go in unto thy brother’s wife, and marry her, and raise up seed to thy brother.
Gen.38: And 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.
1Chr.2: The sons of Judah; Er, and Onan, and Shelah: which three were born unto him of the daughter of Shua the Canaanitess. And Er, the firstborn of Judah, was evil in the sight of the LORD; and he slew him.