Exodus 28:27-28

27And thou shalt make two rings of gold, and shalt put them on the two shoulder-pieces of the ephod underneath, in the forepart thereof, close by the coupling thereof, above the skilfully woven band of the ephod. 28And they shall bind the breastplate by the rings thereof unto the rings of the ephod with a lace of blue, that it may be upon the skilfully woven band of the ephod, and that the breastplate be not loosed from the ephod.