Judges 8:27

And Gideon made an ephod thereof
That is, of some of this gold; for such a quantity could never have been expanded on an ephod only, even taking it not for a linen ephod, but such an one as the high priest wore, made of gold, of blue, purple, and scarlet, and fine twined linen, with curious work, together with a curious girdle of the same work; unless we suppose such a breastplate with it, of twelve precious stones, as Aaron had; and with little images of teraphim or cherubim in it, as Dr. Spencer thinks ^F9. The Jewish commentators generally understand this ephod to be made as a memorial of the great salvation God had wrought by his hands for Israel, and of the wonderful things done by him; so Jarchi, Kimchi, and Ben Gersom; but such a garment, whether worn by him, or hung up in some certain place, seems not so proper and pertinent to perpetuate the memory of his victories, as a monument or pillar would have been; it looks therefore more likely to be done with a religious view, which afterwards was perverted to superstitious uses; and whereas Gideon had built an altar already by the command of God, and had sacrificed upon it, he might think himself authorized as a priest, and therefore provided this ephod for himself; or however for a priest he might think of taking into his family, and so use it as an oracle to consult upon special occasions, without going to Shiloh, the Ephraimites having displeased him in their rough expostulations with him; and so R. Isaiah interprets it of a kind of divination or oracle which gave answers:

and put it in his city, even in Ophrah;
hung it up in some proper place as a monument of his victories, as is generally thought; or in a structure built on purpose for it, to which he might resort as to an oracle:

and all Israel went thither a whoring after it:
made an idol of it and worshipped it, and so committed spiritual fornication, which is idolatry. Some render it, "after him" ^F11; not after the ephod, but after Gideon; that is, after his death, so Jarchi; no ill use was made of it in Gideon's time, though he cannot be altogether excused from sin and weakness in making it; but after his death it was soon made an ill use of:

which thing proved a snare to Gideon and to his house;
it was a snare to him if he consulted it as an oracle, which could not be without sin, since the only Urim and Thummim to be consulted were in the breastplate of the high priest at the tabernacle; and it was what led his family into idolatry, and was the ruin of it, as well as it reflected great discredit and disgrace upon so good and brave a man: some read the words ^F12: "to Gideon, that is, to his house"; or family; he being so good a man himself, it is not thought that he could be ensnared into idolatry itself; though it is apparent that men as wise and as good have fallen into it, as particularly Solomon.