Isaiah 22:22. The key of the house of David will I lay upon his shoulder; so he shall open, and none shall shut; and he shall shut, and none shall open.
Oriental keys being usually large (see note on Judges 3:25, #224), it is often a matter of convenience to carry them on the shoulder. As the possession of a key may be taken as evidence of property or of trust, the key became an emblem of wealth or authority. Eastern merchants are often seen carrying keys on the shoulder. In the text, Shebna, the treasurer of Hezekiah, is warned that Eliakim shall carry “the keys of the house of David”; that is, that he should become treasurer in Shebna’s place. This is a figurative way of expressing what is said in the twenty-first verse: “I will commit thy government into his hand,” which expression is itself partly figurative, the hand being the emblem of power. The idea contained in both these passages is expressed in Isaiah 9:6, where it is said of the Messiah, “The government shall he upon his shoulder.” The word keys is used figuratively to denote authority in Matthew 16:19, where Christ says to Peter: “I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven; and whatsoever thou shalt loose on earth shall be loosed in heaven.”
See also Revelation 1:18; 3:7; 9:1; 20:1.