Exodus 39:21-23

New Century Version

²¹ They used a blue ribbon and tied the rings of the chest covering to the rings of the holy vest, connecting it to the woven belt. In this way the chest covering would not swing out from the holy vest. They did all these things the way the Lord commanded.

²² Then they made the outer robe to be worn under the holy vest. It was woven only of blue cloth. ²³ They made a hole in the center of the outer robe, with a woven collar sewn around it so it would not tear.