The verb gadar means to build a wall, to enclose or fence in. The related noun geder refers to a wall, especially a dry-stone retaining wall or boundary wall. Used both literally and figuratively for protection and restriction.
The imagery of walls in Scripture runs from protective enclosure to prophetic judgment. God is described as a wall of fire around Jerusalem (Zechariah 2:5). The collapse of a wall signals divine withdrawal: 'Why have you broken down its walls?' (Psalm 80:12). Ezekiel uses gadar when he condemns false prophets who fail to 'repair the wall' (Ezekiel 13:5) — those who should stand in the breach but do not. Nehemiah's wall-building is simultaneously spiritual renewal and physical security. The righteous person who 'repairs the breach, restores streets to dwell in' (Isaiah 58:12) becomes a key image of covenant faithfulness.