What does Revelation 21:17 mean?
The angel also measured the wall that surrounds New Jerusalem. Although an angel measured the wall, he used human measurements. The city's wall is 144 cubits thick, which is about 216 feet or almost 66 meters. Generally, a wall is constructed to provide security and/or privacy. But most walls are only a foot (30 cm) or less thick. The massive size of these walls not only implies strength, it suggests the enormous scale of the rest of the city.When Nehemiah heard that Jerusalem's walls were broken down, he became distraught and undertook the task of restoring them (Nehemiah 1:1–4). Even the threat of enemy aggression failed to deter him from the rebuilding effort (Nehemiah 4:15–16). He wanted Jerusalem to be secure. It was common for watchmen to be posted on city walls in order to detect an approaching enemy and sound an alarm. New Jerusalem's extremely thick wall emphasizes the city's security, and the absence of watchmen on the wall emphasizes the fact that God is its protector.