Isaiah 31:1 says,

¹ Woe to those who go down to Egypt for help and rely on horses, and trust in chariots because they are many and in horsemen because they are very strong, but they do not look to the Holy One of Israel, nor seek the Lord!

Here the prophet again chides Judah and King Hezekiah for sending ambassadors to Zoan and Hanes (Isaiah 30:4) to seek their help against the Assyrian threat. If the king had sought the word of the Lord from the prophet at this time, rather than waiting until the Assyrians surrounded Jerusalem, he and the entire city and countryside would have avoided much trouble.

The delay, however, gave the Assyrians time to invade Judah and to deport most of the Judeans to Assyria. 2 Kings 18:13 says,

¹³ Now in the fourteenth year of King Hezekiah, Sennacherib king of Assyria came up against all the fortified cities of Judah and seized them.

The Assyrians took 46 walled cities of Judah and deported more than 200,000 of Judah’s artisans and skilled workers to bolster Assyria’s economy. King Sennacherib’s own record says:

As for Hezekiah the Judahite, who did not submit to my yoke: forty-six of his strong, walled cities, as well as the small towns in their area, which were without number, by levelling with battering-rams and by bringing up siege-engines, and by attacking and storming on foot, by mines, tunnels, and breeches, I besieged and took them. 200,150 people, great and small, male and female, horses, mules, asses, camels, cattle and sheep without number, I brought away from them and counted as spoil. (Hezekiah) himself, like a caged bird I shut up in Jerusalem, his royal city.

http://helpmewithbiblestudy.org/17Archeology/InscriptionAnnalsSennacherib.aspx

This deportation could have been avoided by seeking a word from “The Holy One of Israel,” as the prophet says. It is not that Hezekiah was an evil king. In fact, he was one of their most godly kings. But even believers need to learn how to depend on God, especially when the people expect them to rely on fleshly “horses.”

Multiplying Horses and Wives

God’s law had instructed the kings not to “multiply horses” (Deut. 17:16), which would only bring the nation in bondage to the flesh. The law did not specify how many horses a king was allowed to have, because that would have depended on the heart of the king himself. One king might have had a hundred horses while still relying on God to protect the nation, while another king with just two horses might have relied upon the flesh.

King Solomon established a bad precedent, for we read in 1 Kings 10:26-29,

²⁶ Now Solomon gathered chariots and horsemen; and he had 1,400 chariots and 12,000 horsemen, and he stationed them in the chariot cities and with the king in Jerusalem. ²⁷ The king made silver as common as stones in Jerusalem, and he made cedars as plentiful as sycamore trees that are in the lowland. ²⁸ Also Solomon’s import of horses was from Egypt and Kue, and the king’s merchants procured them from Kue for a price. ²⁹ A chariot was imported from Egypt for 600 shekels of silver, and a horse for 150; and by the same means they exported them to all the kings of the Hittites and to the kings of the Arameans.

Solomon also had too many idolatrous wives who turned his heart away from God (1 Kings 11:1, 2, 3). The law had commanded the kings not to multiply wives (Deut. 17:17), but again it did not specify how many were too many.

Scripture tells us, however, that his wives turned his heart away from God, and his horses caused him to rely upon the flesh. These things are written for our learning, so that we do not follow his example.

God’s Response

Isaiah 31:2 says,

² Yet He [God] also is wise and will bring disaster and does not retract His words but will arise against the house of evildoers and against the help of the workers of iniquity.

The wisdom of men is to build up the nation’s military to protect the nation. But God too “is wise” in a different way. He brings disaster to the nation that relies upon its strong military. God “does not retract His words.” He does not repeal His law to accommodate their carnal ways but will certainly “arise against the house of evildoers.”

Isaiah does not directly accuse the king of being an evildoer but sets forth a general principle against anyone who ceases to trust God for protection. Likewise, God says He will come against “the help of the workers of iniquity,” thereby telling us that fleshly help comes from “workers of iniquity.” Isaiah 31:3 says,

³ Now the Egyptians are men and not God, and their horses are flesh and not spirit; so the Lord will stretch out His hand, and he who helps will stumble and he who is helped will fall, and all of them will come to an end together.

Men and horses are fleshly, the prophet says, and this is echoed in the writings of the Apostle Paul, who developed this theme centuries later. Paul’s understanding was shaped first by the law and secondly by Isaiah more than any other prophet. He received the insight that such “flesh” originated in Adam, the one who was made “a living soul” (Gen. 2:7, KJV; 1 Cor. 15:45).

Paul understood that the “old man” (Rom. 6:6, KJV) was fleshly and was incapable of receiving spiritual revelation. Why? Because, as Isaiah put it, the flesh is “not spirit.” Only spirit can understand spiritual things (1 Cor. 2:14-16). This is why we must be begotten from above, even as Jesus Himself was begotten by the Holy Spirit (Matt. 1:18). This creates a “new man” (Eph. 4:24, KJV) that is a spiritual entity with the capability of grasping spiritual revelation.

Isaiah tells us that “the Lord will stretch out His hand,” a Hebrew metaphor that means He will cause them to “stumble” and “fall” and “come to an end.” Regardless of how He does this or who He uses to accomplish His purpose, God is given the credit for doing it. The lesson is that God will show us that the flesh cannot save us. We must put our trust in God and follow His instructions given in the law and the prophets.

Jerusalem’s True Protector

Isaiah 31:4-6 says,

⁴ For thus says the Lord to me, “As the lion or the young lion growls over his prey, against which a band of shepherds is called out, and he will not be terrified at their voice nor disturbed at their noise, so will the Lord of hosts come down to wage war on Mount Zion and on its hill.” ⁵ Like flying birds, so the Lord of hosts will protect [ganan, “to cover, defend, surround”] Jerusalem. He will protect and deliver it; He will pass over and rescue it. ⁶ Return to Him from whom you have deeply defected, O sons of Israel.

When a lion had taken a lamb as its prey, it would lay claim to it and “a band of shepherds” could not chase away the lion with their shouts and noise. So also, when God wages war against the enemies of Mount Zion, no shouting or noise can chase Him away.

Isaiah’s second metaphor pictures God hovering over His brood to defend it against predators. The same metaphor is seen in Deut. 32:11,

¹¹ Like an eagle that stirs up its nest, that hovers over its young, He spread His wings and caught them, He carried them on His pinions.

Because God has promised to be the Protector of His people, Isaiah admonishes the nation to put their trust in Him. Because the people were putting their trust in the flesh, the prophet says to “return to Him from whom you have deeply defected.”

Isaiah 31:7 continues,

⁷ For in that day every man will cast away his silver idols and his gold idols, which your sinful hands have made for you as a sin.

In other words, in the day that the people stop trusting in idols and the flesh in general, God will protect them. Until then, God allows the people to try to protect themselves by the power of fleshly “horses.” So when Hezekiah was finally desperate enough to seek God’s help, the tide turned, and God defended Jerusalem miraculously.

Isaiah 37:36 says,

³⁶ Then the angel of the Lord went out and struck 185,000 in the camp of the Assyrians; and when men arose early in the morning, behold, all of these were dead.

The normal pattern, it seems, is for us to continue relying on the flesh until we reach the point of utter disaster. When all else fails, we turn to God as a last resort.

Isaiah 31:8, 9 concludes,

⁸ “And the Assyrian will fall by a sword not of man, and a sword not of man will devour him. So he will not escape the sword, and his young men will become forced laborers. ⁹ His rock will pass away because of panic, and his princes will be terrified at the standard,” declares the Lord, whose fire is in Zion and whose furnace is in Jerusalem.

This prophecy was fulfilled later, when the Assyrian army was destroyed, not by the fleshly swords in battle but by a spiritual sword. The silent sword of the angel killed 185,000 Assyrian troops during the night. There was no sound of battle. The survivors, including Sennacherib himself, “departed and returned home and lived at Nineveh” (Isaiah 37:37). He was later assassinated by his sons, and his son Esarhaddon took the throne (Isaiah 37:38).

When the prophet says, “his rock will pass away,” the word translated “rock” is not tsur (“rock, fortress, castle”) but sehlah, which comes from the root word “to be lofty.” It refers to a rocky cliff or stronghold, and the prophet used the word to picture metaphorically the Assyrian army falling off a cliff.

The Assyrian army got “burned” in the furnace of God at Jerusalem.