Exodus 39:21-23

Revised Geneva Translation

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.

²³ And the hole of the robe was in the middle of it, as the collar of a coat of mail, with an edge around the collar, so that it would not tear.