Exodus 39:21-23

Amplified Bible, Classic Edition

²¹ They bound the breastplate by its rings to those of the ephod with a blue lace, that it might lie upon the skillfully woven band of the ephod and that the breastplate might not be loosed from the ephod, as the Lord commanded Moses.

²² And he made the robe of the ephod of woven work all of blue.

²³ And there was an opening [for the head] in the middle of the robe like the hole in a coat of mail, with a binding around it, that it should not be torn.