Jamieson, Fausset and Brown on Judges 8:27

27. Gideon made an ephod thereof, and put it in his city, ... Ophrah--That no idolatrous use was in view, nor any divisive course from Shiloh contemplated, is manifest from Jud 8:33. Gideon proposed, with the gold he received, to make an ephod for his use only as a civil magistrate or ruler, as David did (1Ch 15:27), and a magnificent pectoral or breastplate also. It would seem, from the history, that he was not blamable in making this ephod, as a civil robe or ornament merely, but that it afterward became an object to which religious ideas were attached; whereby it proved a snare, and consequently an evil, by perversion, to Gideon and his house [Taylor, Fragments].