There is a tradition that King Hezekiah hid away a Sefer Refuot, a Book of Remedies, containing cures for nearly every disease. To modern ears this sounds cruel — why withhold healing? But the rabbis defended the act on moral grounds.
When people could open a book and dissolve their suffering with a recipe, they stopped examining the conduct that brought the suffering. The edge of judgment dulled. The sinner never felt the weight of his sin, because the consequence could be bought off at the apothecary. Hezekiah, the reformer-king, wanted his people to feel their lives again.
The same chronicle tells that Hezekiah stopped the aqueduct of Gihon when Sennacherib’s army approached Jerusalem (2 Chronicles 32:3-4). The inhabitants of the city did the same thing, the old chroniclers note, when the Crusaders besieged Jerusalem in 1099 CE. Rashi, however, asks a sharp question: why is this not praised? Because, Rashi answers, Hezekiah should have trusted God’s own promise: “I will defend the city” (2 Kings 19:34). Stopping the water was prudent. It was also, for a king of Judah, a small failure of faith.
Healing withheld to teach the soul, water withheld to save the body — Jerusalem remembers both, and judges both.