Albert Barnes Commentary 2 Kings 19:37

"And it came to pass, as he was worshipping in the house of Nisroch his god, that Adrammelech and Sharezer smote him with the sword: and they escaped into the land of Ararat. And Esar-haddon his son reigned in his stead." — 2 Kings 19:37 (ASV)

The death of Sennacherib, which took place many years later (680 B.C.), is recounted here because, from the divine perspective, it is the sequel to his Syrian expeditions.

Nisroch his god — Nisroch has not yet been identified with any known Assyrian deity. The word may not be the name of a god at all, but rather the name of the temple, as Josephus understood it. Assyrian temples were almost all distinguished by special names. If this is the true solution, the translation should read: "As he was worshipping his god in the house of Nisroch."

They escaped into the land of Armenia—literally, "the land of Ararat," the northeastern portion of Armenia where it bordered Media. The Assyrian inscriptions show that Armenia was independent of Assyria at this time and could therefore offer a safe refuge to the rebels.

Esarhaddon (or Esar-chaddon) is, beyond a doubt, the Asshur-akh-iddin of the inscriptions, who calls himself the son and appears to be the successor of Sin-akh-irib. He began his reign with a struggle against his brother Adrammelech and occupied the throne for only thirteen years, when he was succeeded by his son, Sardanapalus or Asshur-bani-pal. He waged war against Phoenicia, Syria, Arabia, Egypt, and Media, and built three palaces: one at Nineveh, and the others at Calah and Babylon.