Lamentations 2:8 (ESV)

8 The LORD determined to lay in ruins the wall of the daughter of Zion; he stretched out the measuring line; he did not restrain his hand from destroying; he caused rampart and wall to lament; they languished together.

After centuries of warnings, the Lord had now “determined” (decided) to destroy the city. He did this in a very planned and precise way. As a builder who carefully measures before he starts building, the Lord measured the walls in order to destroy them. The walls that were supposed to protect the city, were destroyed—and right after that, the Lord drew back his hand to let the enemy come and do what they wished. 

The Lord can today also make the faithless church weak before her spiritual enemies.