New Defender's Study Bible Notes
22:22 the key. The “key,” hanging on the shoulder, was symbolic of governmental authority (compare Isaiah 9:6), giving access to the treasures of the kingdom. Eliakim becomes a type of Christ, who alone has full authority over “the house of David.”
22:22 none shall open. This particular authority of Eliakim is quoted, in Revelation 3:7, 8, assuring faithful believers in Christ that it is Christ alone, having the key of David, who can open and shut doors.