Exodus 28:27-28

27And two rings of gold shalt thou make, and shalt put them upon the two shoulder-pieces of the ephod underneath, to the front thereof just by the coupling thereof, above the girdle of the ephod.

28And they shall bind the breastplate with its rings to the rings of the ephod with a lace of blue, that it may be above the girdle of the ephod, and that the breastplate be not loosed from the ephod.