In that day shall the LORD defend the inhabitants of Jerusalem; and he that is feeble among them at that day shall be as David; and the house of David shall be as God, as the angel of the LORD before them.
In that day shall the Lord defend the inhabitants of Jerusalem. Jerusalem, however, also shall be specially strengthened against the foe.
And he that is feeble among them at that day shall be as David - to the Jew the highest type of strength and glory on earth (2 Samuel 17:8, "a man of war;" 2 Samuel 18:3; such shall the weakest citizen of Jerusalem become; Joel 3:10).
And the house of David shall be as God, as the angel of the Lord before them - the Divine Angel that went "before them" through the desert, the highest type of strength and glory in heaven (Exodus 23:20; Exodus 32:34). "The house of David" is the "prince" and his family sprung from David (Ezekiel 45:7; Ezekiel 45:9). David's house was then in a comparatively weak state.