Exodus 28:27-28

27And you shall make two rings of gold, and attach them in front to the lower part of the two shoulder pieces of the ephod, at its seam above the skillfully woven band of the ephod.

28And they shall bind the breastpiece by its rings to the rings of the ephod with a lace of blue, so that it may lie on the skillfully woven band of the ephod, so that the breastpiece shall not come loose from the ephod.