Er (Hebrew: ער, ʻEr; "Name means::awake") (Born::Abib 2266 AM—Died::Abib 2281 AM) was the first-born son of Judah by an unknown Canaanitish woman.
The story of Er in the Bible is brief: Judah arranged for him to marry a young woman named Tamar. But Er acted wickedly, and God put him to death. (Genesis 38:6-7 )
The Bible does not say specifically what Er's wicked act was. The Testament of Judah and the Book of Jubilees both state that Er simply refused all intercourse with Tamar, because he resented having her, and not another Canaanitish woman, for a wife (Testament of Judah 2:10, Book of Jubilees 41:1-2). Other commentators suggest that Er practiced the same form of contraception that his younger brother Onan would later practice when Judah asked him to marry Tamar to satisfy the levirate obligation to her.