C. F. Keil and Franz Delitzsch on Exodus 28:39

Exo 28:39

In addition to the distinguishing dress of the high priest, Aaron was also to wear, as the official costume of a priest, a body-coat (cetoneth) made of byssus, and woven in checks or cubes; the head-band (for the diadem), also made of simple byssus; and a girdle (abnet, of uncertain etymology, and only applied to the priest’s girdle) of variegated work, i.e., made of yarn, of the same four colours as the holy things were to be made of (cf. Exo 39:29).