Here "hand" represents power or control. AT: "from the power of Sennacherib ... from the power of all others" or "from Sennacherib ... from all others" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The abstract noun "rest" can be translated as "peacefully." AT: "caused them to live peacefully with all the people of the nations around them" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])