Charles Ellicott Commentary Exodus 28:14

"and two chains of pure gold; like cords shalt thou make them, of wreathen work: and thou shalt put the wreathen chains on the settings." — Exodus 28:14 (ASV)

Chains ... at the ends. —Rather, chains of equal length, or, perhaps, of wreathen work.

Of wreathen work. —Heb., after the manner of a rope. Such chains are often seen around the necks of Persian officials in the Persepolitan sculptures, and appear also to have been used by the dignitaries of Egypt. They were composed of a number of gold wires twisted together. The chains mentioned here are the same as those mentioned in Exodus 28:22-25. Their purpose was to attach the two upper corners of the breastplate to the upper part of the ephod.