Exodus 39:21-23

New American Standard Bible

²¹ And they bound the breastpiece by its rings to the rings of the ephod with a violet cord, so that it would be on the woven band of the ephod, and that the breastpiece would not come loose from the ephod, just as the Lord had commanded Moses.

^22 (A)Then he made the robe of the ephod of woven work, all of violet; ^23 (B)and the opening of the robe was at the top in the center, as the opening of a coat of mail, with a binding all around its opening, so that it would not be torn.