And he brought forth the people that were therein, and put them to work with saws, and with picks of iron, and with axes of iron, and made them toil at the brick kilns: and thus did he unto all the cities of the children of Ammon. So David and all the people returned unto Jerusalem.

Draw your water for the siege, fortify your strongholds: go into the clay, and tread the mortar, make strong the brick kiln.