דברי הימים ב, פרק ל״ב, פסוק ל׳

Facing an impending siege, King Hezekiah undertook a major engineering project to secure Jerusalem's water supply while denying it to the enemy outside. He began by sealing off the spring that served as the source of the water [מצודת דוד, ביאור שטיינזלץ]. The stream of the Gihon had two branches, and the king intentionally chose to block the upper one [רד״ק]. By completely drying up the original riverbed [רלב״ג], he ensured that the invading forces would be left without access to this vital resource during their attack [ביאור שטיינזלץ].

Once the water was blocked from the outside, Hezekiah redirected its flow straight down and westward into the City of David. The primary approach among commentators is that this was achieved through a remarkable underground engineering feat, involving the excavation of subterranean channels and a tunnel [רלב״ג, רד״ק, ביאור שטיינזלץ]. These hidden pathways safely transported the water to the Siloam pool, located on the western side of the city [מלבי״ם].

This dramatic alteration of the city's landscape was an independent initiative. Hezekiah acted on his own accord, as the sages of Israel at the time opposed his decision to block the Gihon [מלבי״ם]. However, this perspective is debated; other traditions suggest he did consult with his officers and the sages beforehand. Regardless of the human disagreement, tradition maintains that God ultimately approved of the king's action [רד״ק]. In the end, Hezekiah found great success in the vast majority of his endeavors [מצודת דוד]. Despite the lack of full consensus from the sages, his achievements flourished because God wanted to test him, waiting to see if the king would rely on Him alone rather than depending entirely on human strategies [מלבי״ם].