Rashi on Exodus 28:8/רש"י על שמות כ״ח:ח׳

1וחשב אפדתו This signifies, and the girdle by means of which he bedecks it (the ephod) and puts it in order for the priest and adorns him (cf. Rashi on v. 4).

2אשר עליו WHICH WAS UPON IT — above on the edge of the apron: this is therefore the girdle.

3כמעשהו ACCORDING TO THE WORK THEREOF — as the weaving of the apron — the work of an artist and of the five materials — so the weaving of the belt, also, was the work of an artist and of the five materials.

4ממנה יהיה IT SHALL BE OF THE SAME — it shall be woven together with it, and one shall not weave it separately, and join its afterwards.