Isaiah 37:9
ESV
Now the king heard concerning Tirhakah king of Cush, "He has set out to fight against you." And when he heard it, he sent messengers to Hezekiah, saying,
NIV
Now Sennacherib received a report that Tirhakah, the king of Cush, was marching out to fight against him. When he heard it, he sent messengers to Hezekiah with this word:
NASB
Now he heard them say regarding Tirhakah king of Cush, 'He has come out to fight against you,' and when he heard it he sent messengers to Hezekiah, saying,
CSB
The king had heard concerning King Tirhakah of Cush, "He has set out to fight against you." So when he heard this, he sent messengers to Hezekiah, saying,
NLT
Soon afterward King Sennacherib received word that King Tirhakah of Ethiopia was leading an army to fight against him. Before leaving to meet the attack, he sent messengers back to Hezekiah in Jerusalem with this message:
KJV
And he heard say concerning Tirhakah king of Ethiopia, He is come forth to make war with thee. And when he heard it, he sent messengers to Hezekiah, saying,
NKJV
And the king heard concerning Tirhakah king of Ethiopia, “He has come out to make war with you.” So when he heard it, he sent messengers to Hezekiah, saying,
What does Isaiah 37:9 mean?
Sennacherib and the Assyrian army were at Lachish when his messenger went to Jerusalem to taunt and discredit King Hezekiah and the Lord (Isaiah 36:1–3). The plan had apparently been to move the army to Jerusalem, a moderate distance away, when the operation at Lachish was concluded. The messenger had been sent to provoke Hezekiah or his people into surrendering quickly to avoid a prolonged siege or possible resistance (Isaiah 36:13–15). Now Sennacherib decides he must change that plan slightly. He hears that the king of Cush, Tirhakah, is coming to take a stand against the Assyrians. Sennacherib chooses to deal with this new threat first before heading to Jerusalem.Several things are happening at once in this scenario. First, the king of Cush—or Ethiopia—was the king of Egypt. Secular sources show that Tirhakah became king of Egypt in or around 689 BC. That is after the events described in this story. At this time, Tirhakah was likely the commander of Egypt's army. Isaiah seems to have used his title at the time of drafting the book, not at the time of the event.
Also, scholars debate how involved Egypt was in Judah's defense against the Assyrians. Most scholars believe the Assyrians overwhelmed the Egyptians (2 Kings 19:9) in a battle at a place called Eltekeh. This would be sometime before the siege of Jerusalem, meaning it had already happened by this point in Isaiah's story. If so, the arrival of Tirhakah would mean that Egypt sent a second wave to take on Sennacherib.
Since Tirhakah is not mentioned again by Isaiah, it's also possible that this second confrontation between the Egyptians and the Assyrians at this time never took place, after all. Was this the rumor the Lord had said that Sennacherib would believe (Isaiah 37:7)? If so, some time had passed between Sennacherib acting on the rumor and finally dying in Nineveh by the sword.
In any case, it seems Sennacherib did not attack Jerusalem as soon as he intended. To be sure Hezekiah didn't think he was being spared, Sennacherib sent a letter to Judah's king. He warned Hezekiah not to start hoping that Jerusalem was safe just because the attack was delayed. He wanted to keep Hezekiah's spirits and courage low.
