Observe how often it is repeated, that all this was in conformity to the express command of God. See Exodus 28:1 and the notes upon it from Exodus 28:31-35.
Exodus 39:22-26
22 And he made the robe of the ephod of woven work, all of blue.
23 And there was an hole in the midst of the robe, as the hole of an habergeon, with a band round about the hole, that it should not rend.
24 And they made upon the hems of the robe pomegranates of blue, and purple, and scarlet, and twined linen.
25 And they made bells of pure gold, and put the bells between the pomegranates upon the hem of the robe, round about between the pomegranates;
26 A bell and a pomegranate, a bell and a pomegranate, round about the hem of the robe to minister in; as the LORD commanded Moses.