'Twelve' in the Bible

{To the chief Musician. On Shushan. Testimony. Michtam of David; to teach: when he strove with the Syrians of Mesopotamia, and the Syrians of Zobah, and Joab returned, and smote the Edomites in the valley of salt, twelve thousand.} O God, thou hast cast us off, thou hast scattered us, thou hast been displeased: restore us again.