Moses describes conditions under the iron yoke in Deut. 28:49, 50,

⁴⁹ The Lord will bring a nation against you from afar, from the end of the earth, as the eagle swoops down, a nation whose language you shall not understand, ⁵⁰ a nation of fierce countenance who shall have no respect for the old, nor show favor to the young.

The first thing to note is that God takes credit for bringing this far-off nation to put Israel under the iron yoke. Therefore, if Israel wanted to change the situation, they would have to deal with God, not with the oppressor himself. The reason for the captivity was Israel’s carnal desire to live under the laws of men, so God gives them their desire to show them how oppressive men’s laws can be.

God used the iron yoke captivities to distinguish the remnant of grace from those whose hearts remained hardened. And so Moses also speaks prophetically of another aspect of the iron yoke that is little understood. He says the iron yoke is imposed upon them by “a nation whose language you shall not understand” (Deut. 28:49).

The Drunkards of Ephraim

Isaiah gives further understanding of this prophecy in Isaiah 28. This is the great “Pentecostal” chapter of the Old Testament, for it speaks of the unknown “tongue” and God’s purpose for this gift.

Isaiah 28:1 introduces the prophecy by saying, “Woe to the proud crown of the drunkards of Ephraim.” Ephraim was drunk on the wine of foreign gods, whereas they should have been filled with the Spirit. Paul says in Eph. 5:18,

¹⁸ And do not get drunk with wine, for that is dissipation, but be filled with the Spirit.

The contrast and comparison between wine and the infilling of the Holy Spirit is seen everywhere in Scripture. We see it most clearly in Isaiah 28. Israel’s priests and prophets were staggering and reeling from excessive “wine,” when they should have been filled with the Spirit (Isaiah 28:7). Their tables were full of vomit, when their mouths should have been filled with the word of the Lord (Isaiah 28:8).

The prophet goes on to tell us that the people refused to hear the word of the Lord from prophecy given in their own language, and so God said in Isaiah 28:11,

¹¹ Indeed, He will speak to this people through stammering lips and a foreign tongue.

In other words, the people refused to hear prophecy in their own Hebrew language, so God spoke to them in a foreign tongue.

The Sign of Tongues under the New Covenant

The Apostle Paul quotes this verse in 1 Cor. 14:21, saying,

²¹ In the Law it is written, “By men of strange tongues and by the lips of strangers I will speak to this people, and even so they will not listen to Me,” says the Lord.

Paul then concludes,

²² So then tongues are for a sign, not to those who believe, but to unbelievers; but prophecy is for a sign, not to unbelievers, but to those who believe.

Tongues are a sign given to unbelievers, whereas prophecy is a sign to believers.

Where did Paul get this idea? He got it from Israel’s example in Isaiah 28. The majority of the Israelites did not believe Isaiah’s prophecy when it was spoken in their own Hebrew language. They were “scoffers” (Isaiah 28:14). So God gave them the word through the Assyrians, who spoke in “a foreign tongue.” It was a word of divine judgment, for they ordered the Israelites to pack up and move to a foreign land.

In other words, if people will not or cannot hear the word of prophecy in their own language, God will speak to them in an unknown tongue. Therefore, prophecy is given as a sign to believers, while tongues are given as a sign to unbelievers.

The gift of tongues is also a sign to one’s own carnal mind, which is incapable of believing the word of the Lord. The natural (soulish) mind cannot comprehend the things of the Spirit, as Paul tells us in 1 Cor. 2:14,

¹⁴ But a natural [soulish] man does not accept the things of the Spirit of God; for they are foolishness to him, and he cannot understand them, because they are spiritually appraised.

The carnal mind is the “old man” in Rom. 6:6, which we inherited from Adam. It can be very religious, but it cannot comprehend spiritual things. Its religious bent causes it to misunderstand the laws of God, which are spiritual (Rom. 7:14) and turns them into “traditions of men.” Paul also says that this same carnal mind is actually at war with God (Rom. 7:23) on account of its disagreement and unbelief.

Hence, to the unbelieving, carnal mind God speaks in an unknown tongue in order to bring it into captivity. Paul says in 2 Cor. 10:4, 5,

⁴ for the weapons of our warfare are not of the flesh, but divinely powerful for the destruction of fortresses. ⁵ We are destroying speculations and every lofty thing raised up against the knowledge of God, and we are taking every thought captive to the obedience of Christ.

When the carnal mind is judged by the law of God, it is brought into captivity, so that the New Creation Man, having the mind of Christ, may rule in the life of the believer.

Prophecy is a Greater Gift

Once we understand the foundational revelations of Moses and Isaiah, we can then see better how Paul applies them in his letter to the Corinthians. We also can better understand why prophecy is superior to tongues, as Paul says in 1 Cor. 14:5,

⁵ Now I wish that you all spoke in tongues, but even more that you would prophesy, and greater is one who prophesies than one who speaks in tongues, unless he interprets, so that the church may receive edifying.

Even as it would have been better for the Israelites to “hear” the prophecy of Isaiah, rather than to wait for the Assyrians to speak the word of the Lord in an unknown tongue, so also is it better to prophesy in a known language than to receive the word in an unknown tongue. Paul explains also how interpretation can overcome the language barrier. Yet the implication is that the carnal mind is the “unbeliever” within ourselves. Hence, every thought from the carnal mind must be brought into captivity.

The gift of tongues is therefore one of the curses of the law. This does not mean that tongues is an evil thing. Indeed, it is a spiritual gift. Like all of God’s “curses,” it is designed to discipline and correct the unbeliever in order to bring all men into agreement with the mind of God. Moses says that tongues is one of the signs of the iron yoke. Isaiah expands on this idea, applying it to the Assyrians who were called to bring those unbelieving Israelites into captivity.

Paul applies it to us personally, showing that the unbelieving, carnal mind must be brought into an iron-yoke captivity through the gift of tongues, until we are able to hear God’s voice in our own language.