“And they shall make the ephod of gold, of blue and purple and scarlet yarns, and of fine twined linen, skillfully worked.
Directions are here given concerning the ephod, which was the outmost garment of the high priest. Linen ephods were worn by the inferior priests, Sa1 22:18. Samuel wore one when he was a child (Sa1 2:18), and David when he danced before the ark (Sa2 6:14); but this which the high priest only wore was called a golden ephod, because there was a great deal of gold woven into it.
Commenting on Exodus 28:6-14
And they shall make the ephod,.... This was the outermost garment of, all, and was put over the robe; it was a short garment, reaching to the loins, as Kimchi (p); or to the buttocks, as Abarbinel (q); and not to the heels or feet, as Jarchi (r), and Maimonides (s); for Josephus (t) says it was but a cubit long, which was little more...
ephod--It was a very gorgeous robe made of byssus, curiously embroidered, and dyed with variegated colors, and further enriched with golden tissue, the threads of gold being either originally interwoven or afterwards inserted by the embroiderer. It was short--reaching from the breast to a little below the loins--and though destitute of sleeves, retained its position by the support of straps thrown over each shoulder.