Rashi on Isaiah
the light of Israel The Torah in which Hezekiah engages shall become fire for Sennacherib.
Ibn Ezra on Isaiah
The light of Israel. God. Shall be a fire. This refers to the angel that destroyed the Assyrian camp.
Rashi on Isaiah
and his holy one The Holy One, blessed be He. Alternatively, “And his holy one,” refers to the righteous of the generation.