The city of Jerusalem underwent many changes throughout Bible times. When King David captured the city from the Jebusites, it was a relatively small fortress positioned next to the Gihon Spring–a dependable source of water that later enabled the city to withstand various sieges. King Solomon built the temple on a threshing floor north of the city, and the city continued to grow. King Hezekiah eventually expanded the walls to encompass a much larger area and replaced the old Jebusite tunnel with another tunnel (probably called Shiloah) to channel water more securely from the Gihon Spring to the Lower Pool (later called the Pool of Siloam/Shiloah) and the king’s garden. This new tunnel is probably what Isaiah 8:5-8 refers to when it rebukes the people of Judah for rejecting the gently flowing waters of Shiloah to support the Arameans.