Habergeon

The habergeon is a piece of armor — a coat of mail. UPDV renders the older term plainly as "coat of mail," and the references that fall under this umbrella use the garment as a point of comparison rather than describing it for its own sake. The neck-opening of the high priest's robe is described by simile to the bound hole of a coat of mail.

The neck-opening of the priestly robe

The instruction for Aaron's robe gives the simile in plain terms. "And it will have a hole for the head in the midst of it: it will have a binding of woven work round about the hole of it, as it were the hole of a coat of mail, that it is not rent" (Ex 28:32). The reinforced opening of a soldier's coat of mail is the model: a strong woven binding so the fabric does not tear under wear.

The construction account at Ex 39 records that the instruction was carried out the same way: "And the hole of the robe in the midst of it, as the hole of a coat of mail, with a binding round about the hole of it, that it should not be rent" (Ex 39:23). The robe of the high priest takes its durable neck from the pattern of the coat of mail.