Lock

Locks in the ancient world typically consisted of wooden bars or bolts that secured doors from within. The most common mechanism in Palestine and throughout the Near East was a heavy wooden bar that slid across the door into brackets on the door frame (Isa. 45:2; 1 Kings 4:13; Neh. 3:3, 6, 13). A more sophisticated form—the pin tumbler lock—was also used, in which a bar was fitted with holes that could only be lifted by a corresponding wooden key inserted through a hole in the door from the outside (Song 5:4–5). These keys were often large enough to be carried on the shoulder (Isa. 22:22).

Isaiah 22:22 uses the imagery of keys and locking to describe the authority entrusted to Eliakim: I will lay the key of the house of David on his shoulder; he shall open, and none shall shut; and he shall shut, and none shall open. Jesus applies the same language to the keys of the kingdom of heaven given to Peter (Matt. 16:19) and to himself as the holder of the key of David in Revelation 3:7, making the lock and key a significant biblical symbol of authority and access.