2 Chronicles 32:1-3

1 After these things and this faithfulness, Sennacherib king of Assyria came and invaded Judah and besieged the fortified cities, intending to take them for himself.

2 When Hezekiah saw that Sennacherib had come and that he intended to go to war against Jerusalem,

3 he decided, together with his officers and his soldiers, to stop up the water [supply] from the springs which were outside the city [by enclosing them with masonry and concealing them], and they helped him.