Some historical notes on today’s reading:
Hezekiah’s father, Ahaz, voluntarily sent tribute to Assyria and put Judah under the Assyrian yoke (2 Kin 16:6-9). Every year thereafter tribute of the agreed upon amount had to be paid to Assyria or face the consequences of rebellion. Hezekiah had made an alliance with Pharaoh of Egypt; they were both going to stop sending tribute to Assyria, and they were going to help each other to resist the consequences.
This plan and alliance was the occasion of Isaiah’s prophecy recorded in Isa 30:1-5, and following was the LORD’s advice and wisdom to Hezekiah: to trust instead in the LORD God, to seek salvation in returning to Him and in rest in Him (Isa 30:15). Hezekiah followed this advice, did not send tribute to Assyria, relying on the LORD rather than Egypt, and Sennacherib, who was king at the time, came with his army to overthrow Egypt, as the source of rebellions against him, (for Israel had also made an alliance with Egypt in order to defy Assyria) then Judah and Jerusalem.
Sennacherib spent three years in Egypt, and finally prevailed against the Egyptians and Ethiopians, their allies (even though the Ethiopians made him withdraw from one of the Egyptian cities). Sennacherib returned through Judah, besieging one fortified city after another.
While he was thus engaged, he sent his Rabshakeh, or chief of staff, to Jerusalem to induce them to resume the tribute, and not have to suffer the humiliation and defeat of being overcome by Assyria’s superior forces. He pointed out the futility of trusting in Egypt (Isa 36:6), and also that it was futile to trust in the LORD God.
In response to this threat, the LORD spoke through Isaiah, that Sennacherib would hear a rumor, and a spirit of fear would come upon him, and he would return to his own land without waging war against Jerusalem, and in his own land he would fall by the sword (Isa 37:6-7).
After the Rabshakeh departed, Sennacherib did hear a rumor that Tirhakah king of Ethiopia was coming with his army to meet him and make war with him. From Barnes’ Notes on the Bible:
Tirhakah – This king, who, by Eusebius and by most ancient writers, is called Ταρακὸς Tarakos, was a celebrated conqueror, and had subdued Egypt to himself. He reigned over Egypt eighteen years. When Sennacherib marched into Egypt, Sevechus or Sethon was on the throne. Sennacherib having laid siege to Pelusium, Tirhakah came to the aid of the city, and, in consequence of his aid, Sennacherib was compelled to raise the siege and returned to Palestine, and laid siege to Lachish. Tirhakah succeeded Sevechus in Egypt, and was the third and last of the Ethiopian kings that reigned over that country. He probably took advantage of the distracted state that succeeded the death of Sevechus, and secured the crown for himself. This was, however, after the death of Sennacherib. The capital which he occupied was Thebes (see Prideaux’s “Connection,” vol. i. pp. 141, 145, 149. Ed. 1815). As he was celebrated as a conqueror, and as he had driven Sennacherib from Pelusium and from Egypt, we may see the cause of the alarm of Sennacherib when it was rumoured that he was about to follow him into Palestine, and to make war on him there.
When Sennacherib heard the rumor about Tirhakah, he sent a letter to Hezekiah, in essence saying, “Look, don’t let this rumor bolster your strength or encourage you against me, because I am going to take Jerusalem and your God is not going to be able to save you from me.” The LORD’s response to this blasphemy, was to assure Sennacherib that He Himself will put His hook in Sennacherib’s nose and His bridle in his lips, and turn him back by the way which he came (Isa 37:29). For it was the common practice of the Assyrians to lead the kings and nobles that they had taken captive by bridles and hooks which they passed through their noses and lips, like animals, furthering their humiliation and pain.
When Sennacherib encamped before Jerusalem, the angel of the LORD went through the Assyrian camp, and 185,000 of his choice troops were killed in a single night. When the Assyrians who were left got up in the morning, they were surrounded by dead bodies. Thus was fulfilled the word spoken by Isaiah:
“Then Assyria shall fall by a sword not of man,
And a sword not of mankind shall devour him.” Isa 31:8
Sennacherib departed and returned home! And he was killed by the sword in his own land, just as the LORD had said.