Exodus 39:21-23

Lexham English Bible

²¹ And they tied the breast piece by its rings to the rings of the ephod with a blue cord so that the breast piece would be on the waistband of the ephod and not come loose from the ephod, as Yahweh had commanded Moses.

²² And he made the robe of the ephod, weaver’s work, totally of blue yarn. ²³ And the opening of the robe in the middle of it was like the opening of a sturdy garment, with an edge for its opening all around so that it would not be torn.