2 Chron 32:2-6,32 When Hezekiah saw that Sennacherib had invaded and intended to attack Jerusalem, 3 he consulted with his advisers and military officers about stopping up the springs outside the city, and they supported him. 4 A large number of people gathered together and stopped up all the springs and the stream that flowed through the district. They reasoned, “Why should the kings of Assyria come and find plenty of water?” 5 Hezekiah energetically rebuilt every broken wall. He erected towers and an outer wall, and fortified the terrace of the City of David. He made many weapons and shields. 6 He appointed military officers over the army and assembled them in the square at the city gate. 30 Hezekiah dammed up the source of the waters of the Upper Gihon and directed them down to the west side of the City of David. (NET)
Hezekiah saw what Sennacherib did to Israel (Samaria) in 722 BC. Now it’s 714 BC and the Assyrians are setting their sights on Judah. Hezekiah was not about to let the same fate befall Judah. Sennacherib did not besiege Jerusalem until 701 BC. Hezekiah probably spent 12 years or more preparing for the impending Assyrian siege. One of the ways he prepared was to build an underground tunnel from the Gihon Spring outside the city walls to the Pool of Siloam within the city walls. This secret tunnel would supply the Judahites with the water they needed to endure the siege.
Hezekiah’s tunnel was discovered in 1838 by Edward Robinson. Interestingly enough, it still carries water from the Gihon Spring to the Pool of Siloam. The tunnel itself is an amazing feat of engineering. It is 1750 feet long, cut through solid rock 130 feet below ground. The tunnel is S-shaped, and slopes at a consistent 0.6% grade. At some places the ceiling is so short that you have to duck to traverse it, but by the last 160’ feet of the tunnel the ceiling reaches 17’ tall. What is most impressive about the construction of the tunnel is that two teams were digging it simultaneously starting at opposite ends and meeting in the middle. The point at which the two teams met was commemorated with an inscription, which we’ll explore next.