Exodus 28:31-35

“Make the robe for the Ephod entirely of blue, with an opening for the head at the center and a hem on the edge so that it won’t tear. For the edge of the skirts make pomegranates of blue, purple, and scarlet material all around and alternate them with bells of gold—gold bell and pomegranate, gold bell and pomegranate—all around the hem of the robe. Aaron has to wear it when he does his priestly work. The bells will be heard when he enters the Holy Place and comes into the presence of GOD, and again when he comes out so that he won’t die.