A coat of mail was body armour, and it appears in the Bible when a fight is near. In 1 Samuel 17:5, Goliath wears one that weighs five thousand shekels of brass. A few verses later, 17:38, Saul puts one on David, and David sets it aside because it does not fit him. In 1 Kings 22:34 a stray arrow finds the joints of the king’s harness, and no armour can fully protect Ahab from what God has said. Together the verses suggest that strength worn on the body is never the whole answer. Read 1 Samuel 17 for the full scene.
4 verses
And he had an helmet of brass upon his head, and he was armed with a coat of mail; and the weight of the coat was five thousand shekels of brass.
And Saul armed David with his armour, and he put an helmet of brass upon his head; also he armed him with a coat of mail.
And a certain man drew a bow at a venture, and smote the king of Israel between the joints of the harness: wherefore he said unto the driver of his chariot, Turn thine hand, and carry me out of the host; for I am wounded.
And a certain man drew a bow at a venture, and smote the king of Israel between the joints of the harness: therefore he said to his chariot man, Turn thine hand, that thou mayest carry me out of the host; for I am wounded.
Matthew George Easton, 1897
The rendering of a Hebrew word meaning “glittering” (1 Sam. 17:5, 38). The same word in the plural form is translated “habergeons” in 2 Chr. 26:14 and Neh. 4:16. The “harness” (1 Kings 22:34), “breastplate” (Isa. 59:17), and “brigandine” (Jer. 46:4), were probably also corselets or coats of mail. (See ARMOUR.)