In biblical literature, walls serve as significant physical and symbolic structures, representing protection, division, and the strength of a city or nation. They are often mentioned in the context of ancient cities, fortifications, and spiritual metaphors.

1. Walls of Jericho:
The walls of Jericho are among the most famous in the Bible. According to the Book of Joshua, the Israelites, led by Joshua, conquered the city of Jericho by marching around its walls for seven days. On the seventh day, the priests blew their trumpets, and the people shouted, causing the walls to collapse. This miraculous event is recorded in Joshua 6:20: "So when the people heard the sound of the trumpet, they shouted with a great shout. And the wall fell down flat, so that the people went up into the city, every man straight ahead, and they captured the city."

2. Walls of Jerusalem:
Jerusalem's walls have been built, destroyed, and rebuilt multiple times throughout biblical history. King David initially captured the city, but it was his son Solomon who fortified it. Nehemiah later led the effort to rebuild the walls after the Babylonian exile, as described in Nehemiah 4:6: "So we rebuilt the wall until all of it was joined together up to half its height, for the people had a mind to work." The walls of Jerusalem symbolize God's protection and the restoration of His people.

3. Symbolic Significance:
Walls in the Bible often symbolize security and divine protection. In Isaiah 26:1, the prophet speaks of a strong city with salvation as its walls and ramparts: "In that day this song will be sung in the land of Judah: 'We have a strong city; He sets up salvation as walls and ramparts.'" This imagery conveys the idea that God's salvation provides ultimate security for His people.

4. Walls as Division:
Walls can also represent division and separation. In Ephesians 2:14, the Apostle Paul speaks of Christ breaking down the "dividing wall of hostility" between Jews and Gentiles: "For He Himself is our peace, who has made the two one and has torn down the dividing wall of hostility." This metaphorical wall signifies the barriers that separate humanity, which are overcome through Christ's reconciling work.

5. Walls in Prophecy:
Prophetic literature often uses walls to describe future events. In Revelation 21:12, the New Jerusalem is depicted with a great and high wall, symbolizing the eternal security and holiness of God's heavenly city: "It had a great and high wall with twelve gates inscribed with the names of the twelve tribes of Israel."

6. Walls in Personal and Spiritual Life:
In a personal and spiritual context, walls can represent the barriers individuals build around their hearts. Proverbs 25:28 warns, "Like a city whose walls are broken down is a man who does not control his temper." This suggests that self-control and discipline are necessary to maintain spiritual integrity and protection.

Throughout the Bible, walls serve as powerful symbols of God's protection, human division, and the spiritual fortifications necessary for a life of faith. They remind believers of the importance of divine security and the call to break down barriers through the love and reconciliation found in Christ.