Divrey Hayamim Bais 32:2-4

Orthodox Jewish Bible

² And when Chizkiyahu saw that Sancheriv was come, and that he was purposed to make milchamah against Yerushalayim,

³ He took counsel with his sarim and his gibborim to cover over the waters of the springs [Spring of Gihon] which were outside the Ir; and they did support him.

⁴ So there was gathered Am Rav together, who covered the springs, and the wadi that flowed through the midst of HaAretz, saying, Why should the melachim of Assyria come, and find mayim rabbim?