Exodus 39:21

39:21 They bound the breastplate by its rings to the rings of the ephod with a lace of blue, that it might be on the skillfully woven band of the ephod, and that the breastplate might not come loose from the ephod, as Yahweh commanded Moses.
-World English Bible

Other Translation

39:21 And they did bind the breastplate by his rings unto the rings of the ephod with a lace of blue, that it might be above the curious girdle of the ephod, and that the breastplate might not be loosed from the ephod; as the LORD commanded Moses.
-King James Version