2 Chronicles 32:3-5

3 he took counsel with his princes and his mighty men to stop the waters of the fountains which [were] outside the city, and they helped him.

4 So many people gathered together, and they stopped up all the fountains and the brook that ran through the midst of the land, saying, Why should the kings of Assyria come and find much water?

5 Also he strengthened himself and built up all the wall that was broken and caused the towers to be raised up, and another wall outside, and repaired Millo [in] the city of David, and made swords and shields in abundance.