Exodus 28:31-35

31“You are to make the robe of the ephod entirely of blue.

32It is to have a hole for the head in the center, and a binding of woven work around the hole, as a collar, so that it may not be torn.

33On the hem of it you are to make pomegranates of blue, purple and scarlet, all around the hem, with golden bells between them:

34one golden bell and a pomegranate, then another golden bell and a pomegranate, on the hem of the robe all around.

35It must be worn by Aaron whenever he ministers. The sound will be heard when he goes into the holy place before Adonai and when he comes out, so that he does not die.