Exodus 39:20-22

Revised Geneva Translation

²⁰ They also made two other golden rings and put them on the two sides of the ephod, underneath, on the front of it and near its coupling, above the skillfully-woven band of the ephod.

²¹ And they fastened the breastplate (by its rings) to the rings of the ephod, with a lace of blue silk, so that it might be secure upon the skillfully-woven band of the ephod, and so that the breastplate should not come loose from the ephod, as the LORD had commanded Moses.

²² Moreover, he made the robe of the ephod of woven work, entirely of blue silk.