Exodus 39:21-23

New King James Version

²¹ And they bound the breastplate by means of its rings to the rings of the ephod with a blue cord, so that it would be above the intricately woven band of the ephod, and that the breastplate would not come loose from the ephod, as the Lord had commanded Moses.

Making the Other Priestly Garments

^22 (A)He made the ^(B)robe of the ephod of woven work, all of blue. ²³ And there was an opening in the middle of the robe, like the opening in a coat of mail, with a woven binding all around the opening, so that it would not tear.