Then they tied the rings of the breastpiece to the rings of the ephod with a cord of blue yarn, so that the breastpiece was above the waistband of the ephod and would not swing out from the ephod, just as the LORD had commanded Moses.
Jewish Publication Society of America Version (JPS1917) - Exodus 39:21 >And they did bind the breastplate by the rings thereof unto the rings of the ephod with a thread of blue, that it might be upon the skilfully woven band of the ephod, and that the breastplate might not be loosed from the ephod; as the LORD commanded Moses.