Exodus 28:28-30

New International Version

²⁸ The rings of the breastpiece are to be tied to the rings of the ephod with blue cord, connecting it to the waistband, so that the breastpiece will not swing out from the ephod.

²⁹ “Whenever Aaron enters the Holy Place,^(A) he will bear the names of the sons of Israel over his heart on the breastpiece of decision as a continuing memorial before the Lord. ³⁰ Also put the Urim and the Thummim^(B) in the breastpiece, so they may be over Aaron’s heart whenever he enters the presence of the Lord. Thus Aaron will always bear the means of making decisions for the Israelites over his heart before the Lord.