a city wall: the massive outer wall that rings a town, holds off an attacking army, and marks where the city begins
This is the word for a city's outer wall, and in the New Testament it is never used of anything else. In the ancient world a wall was what turned a settlement into a city. It was built of stone or mud brick, thick enough to walk along the top of, and high enough that an attacking army had to break it, climb it, or starve the people behind it. Houses were sometimes built right into it, with windows looking out over the countryside. It is not the wall of a house or a room, which Greek names with a separate word (τοῖχος).
The nine places it appears fall into three scenes, and the wall is doing something different in each one:
- at Jericho the walls simply fall down after Israel circles the city for seven days, and the letter to the Hebrews credits that to faith rather than to siege engines (Hebrews 11:30)
- at Damascus the wall is the obstacle Paul has to get past, and his friends lower him down the outside of it in a basket through a window (Acts 9:25, 2 Corinthians 11:33)
- in John's vision the wall of the new Jerusalem is measured, jeweled, and inscribed with names, so that it reads as a monument rather than as a defense (Revelation 21:12, Revelation 21:17)
That last scene is the surprising one. The wall there is enormous, its twelve foundation stones carry the names of the apostles, and its facing is jasper. Yet the gates set into it are never shut, because nothing is left outside to fear. A structure that everywhere else in the ancient world said "keep out" has become a way of saying whom the city belongs to.