Rezeph
Rezeph is one of the cities the Assyrian king names in his taunting letter against Hezekiah's Jerusalem — a place his fathers had already destroyed, brought up as evidence that no foreign god ever delivers a city in Assyria's path.
Listed Among Assyrian Conquests
The threat is delivered by the same words in two parallel passages. In Kings: "Have the gods of the nations delivered them, which my fathers have destroyed, Gozan, and Haran, and Rezeph, and the sons of Eden who were in Telassar?" (2 Ki 19:12). The Isaiah parallel is identical: "Have the gods of the nations delivered them, which my fathers have destroyed, Gozan, and Haran, and Rezeph, and the sons of Eden who were in Telassar?" (Isa 37:12).
The list places Rezeph in a sequence — Gozan, Haran, Rezeph, Telassar — that the Assyrian king treats as common knowledge. Each city is offered as a test case: their gods did not save them, and Hezekiah is being asked to draw the implied conclusion. The Bible's mention of Rezeph is exhausted by this one taunt, repeated twice; nothing else is said about the city.