The Testament of Solomon (c. 1st-5th century CE) describes a ring, given by Michael, with which Solomon bound demons to build the Temple. The hexagram as Solomon's seal spreads through medieval Jewish, Islamic, and grimoire traditions; the pentagram variant runs parallel. The biblical text itself mentions neither ring nor seal.
The modern shorthand: the Seal as simply the Star of David, Judaism's emblem. The star's rise as a Jewish symbol is largely medieval and later; its career as a Solomonic magic sign is older in the manuscripts, the two careers colliding only recently.
The grimoires' own logic: the seal works because the name behind it works, Solomon as the one licensed by heaven to bind. The sign is a signature, and every later pentacle is a forgery or a franchise of the original authority. Magic's oldest question is not whether the seal works but whose name it bears.
Who owns a symbol, the king who never used it, or the magicians who never stopped?