Midrasch zu Divrej Hajamim II 32:25

Another matter: “Look from the peak of Amana” – this is Abraham in whose regard it is written: “And he believed in the Lord” (Genesis 15:6). “From the peak of Senir” – this is Isaac. Just as Senir is hostile to plowing [soneh nir], so too, Isaac was subject to an ordeal only once. “And Ḥermon” – this is Jacob. Just as all the good of the Ḥermon is in its lower reaches, so too, priesthood is from Jacob, Levites are from Jacob, kingdom is from Jacob.¹¹⁴Jacob was the last of the patriarchs.
“From the dens of lions” – these are Siḥon and Og; just as the lion is haughty, so Siḥon and Og were haughty and mighty, as there was a distance of only one day’s walk between this one and that one, and this one did not come to the aid of that one, and that one did not come to the aid of this one. “From the mountains of leopards” – these are the Canaanites. Just as this leopard is impudent, so the Canaanites were impudent. That is what is written: “Not a man remained in the Ai [or Beit El who did not come out after Israel]” (Joshua 8:17).
Rabbi Berekhya said in the name of Rabbi Elazar: It would have been fitting for Israel to have sung song over the downfall of Siḥon and Og, and it would have been fitting for Hezekiah to have sung song over the downfall of Sennacherib, as it is written: “But Hezekiah did not reciprocate according to the reward bestowed upon him” (II Chronicles 32:25). “As his heart had grown haughty” (II Chronicles 32:25). You see Hezekiah, a king and a righteous man, and you say “as his heart had grown haughty”? Rather, his heart had grown too haughty to sing a song. Isaiah came to Hezekiah and his associates. He said to them: “Sing to the Lord” (Isaiah 12:5). They said to him: Why? “For He has performed grandeur” (Isaiah 12:5). They said to him: It is already “known throughout the land” (Isaiah 12:5). Rabbi Abba bar Kahana said: Hezekiah said: The Torah in which I engage atones for the [absence of] song.¹¹⁵Hezekiah thought that because he had caused Torah to be known throughout the land, he was above singing songs of praise.
Rabbi Levi said: Hezekiah said: Why do we need to recount the miracles and mighty exploits of the Holy One blessed be He? They are already known from one end of the world to the other. Has the sun not stood in the middle of the sky¹¹⁶See II Kings 20:11. and they [thus] saw the miracles and mighty exploits of the Holy One blessed be He to the end of the world?
Rabbi Yishmael ben Rabbi Yosei says in the name of Rabbi Abba: Pharaoh king of Egypt and Tirhaka king of Kush were already involved in that miracle and came to aid Hezekiah. Sennacherib sensed their presence. What did the wicked Sennacherib do to them? At nightfall he bound them; at midnight, the angel emerged and struck Sennacherib’s troops. That is what is written: “The angel of the Lord emerged and smote the Assyrian camp” (Isaiah 37:36). In the morning, Hezekiah arose early and found them bound. He said: It seems that these came only to aid me. He untied them and they went and related the miracles and mighty exploits of the Holy One blessed be He. That is what is written: “Thus says the Lord: The product of Egypt and the merchandise of Kush” (Isaiah 45:14). “The product of Egypt” – this is Pharaoh king of Egypt; “and the merchandise of Kush” – this is Tirhaka king of Kush. “And the Sabeans, men of stature” (Isaiah 45:14) – these are their armies. “Will pass over to you” (Isaiah 45:14) – this is Hezekiah and his associates. “They will be yours (Isaiah 45:14)” – they are already at peace with you. “They will follow you and pass in chains (Isaiah 45:14)” – in manacles. “They will prostrate themselves to you” (Isaiah 45:14) – this is Jerusalem. “They will pray before you” (Isaiah 45:14) – this is the Temple. What would they say? “There is only God with you; there is none other except for God” (Isaiah 45:14). Isaiah said before the Holy One blessed be He: Master of the universe, “indeed [akhen] You are God who conceals Himself” (Isaiah 45:15). What is “akhen”? Where [ekhan] are You hiding, God? Indeed, You have the dynamism, and You conceal Yourself? [God] said to him: “God of Israel, Savior” (Isaiah 45:15) – I will then take vengeance.
Rabbi Yehoshua ben Levi said: Had Hezekiah recited song over the downfall of Sennacherib, he would have become the messianic king and Sennacherib [would have been] Gog and Magog, but he did not do so. Rather, he said: “Now I know that the Lord has rescued His anointed one.… Some come on chariots [and some on horses but we will make mention of the name of the Lord our God]” (Psalms 20:7–8). What is written thereafter? “Deliver us, Lord. The King will answer us on the day we call” (Psalms 20:10).¹¹⁷These verses are attributed here to Hezekiah, and he refers to a future king as “His anointed one [meshiḥo],” an allusion to the Messiah, in realization that he himself would no longer be able to be the Messiah (Maharzu).