The religious reform, instituted by Hezekiah, was an attempt to centralize worship in Jerusalem. This attempt made the people dependent upon Jerusalem. It also increased the economic power of Jerusalem. Religious reforms placed King Hezekiah in total control of the economy and the food supply. Is it possible that these efforts were part of an overall plan to prepare for the invasion of the Assyrians?
The text in 2 Chronicles 32:1-9 indicates that many preparations, including the building of water courses, aqueducts and the Gihon to Siloam tunnel dug through solid rock, were started and completed before the siege began because the invasion of Sennacherib was believed to be imminent. The invasion in 701 BC that included the siege of Lachish is much too close in time to the siege of Jerusalem to have allowed time to complete the vast public works programs which Sennacherib's threats caused Hezekiah to create. Thus the preparations for the impending attack by the Assyrians occupied a lengthy period of time. The preparations probably began before Hezekiah announced that he was suspending tribute payments knowing such announcement would result in an invasion.
Gospel of Luke