“Ephod” From Concise Bible Dictionary:
1. The ephod worn by the high priest. Minute instructions were given as to its construction. It was to be made of gold, blue, purple, scarlet, and fine twined linen, with cunning work. The gold was beaten into thin plates and then cut into wires, which were woven into the fabric. Its GIRDLE was also to be of the same materials with embroidered work. On the shoulders were fastened two stones, engraved with the names of the twelve tribes, six names on each stone; so that whenever Aaron wore the ephod the twelve tribes were represented. We read also of the ROBE OF THE EPHOD, which was all of blue, and along the bottom of which were pomegranates of blue, purple, and scarlet, with bells of gold between them. The robe was doubtless much longer than the ephod, which is supposed not to have reached the knees, and which was worn over the robe, and the BREASTPLATE over the ephod. There was also a broidered coat of fine linen; this was worn under the robe. These with the miter constituted Aaron’s garments “for glory and for beauty” (Ex. 28:1-39). Apparently the ordinary priestly garments worn by Aaron’s sons are also said to be “for glory and for beauty” (Ex. 28:40).
In the various textures of the ephod there are typified divine righteousness, heavenliness, royalty, dignity, and the graces of the Spirit: the virtues that characterized the Lord Jesus. Inseparably attached to the ephod was the breastplate, in which were the Urim and Thummim; thus in wearing the ephod the judgment of the children of Israel was borne before the Lord, according to His lights and perfections. Though not worn on ordinary occasions, it was required when directions were sought from God (compare 1 Sam. 21:9). Thus receiving answers from God is also associated with the Urim and Thummim, which were placed in the breastplate (Ex. 28:28: Compare Num. 27:21; 1 Sam. 28:6; Ezra 2:63; Neh. 7:65). The word “Ephod” is the same in the Hebrew, and is from “to bind round or gird,” so that its meaning does not seem to go beyond “a priestly garment” (Ex. 29:5; Ex. 35:9, 27; Ex. 39:2-22; Lev. 8:7; 1 Sam. 2:28).
2. Besides the above, which may be called the ephod, there were others which the priests wore, but which are not described (1 Sam. 14:3; 1 Sam. 22:18; 1 Sam. 23:6,9; 1 Sam. 30:7; Hos. 3:4). David, on the occasion of bringing up the ark, wore a linen ephod (2 Sam. 6:14; 1 Chron. 15:27). Samuel also, when only a child, wore a linen ephod (1 Sam. 2:18). In all the above passages the ephod bears the character of a priestly garment, though David was not of the tribe of Aaron. Type of the kingly Priest of the order of Melchisedec.
3. A strange deviation from the above was the ephod which Gideon made of the gold, the ornaments, and the purple raiment taken from the Midianites, after which all Israel went astray, and which became a snare to Gideon and his house (Judg. 8:27). Still worse was the case of Micah who, having a house of gods, made an ephod, and consecrated one of his sons to be priest. A Levite coming to the house fell in with the whole arrangement, and pretended to inquire of God by the ephod. When the gods were stolen by the children of Dan, the Levite was glad to accompany the idols and the ephod, and to be a priest to this tribe. Thus was the priestly garment that should have been restricted to the service of Jehovah associated with idolatry (Judg. 17:5; Judg. 18:14-20).