Let me get this posted then I'll try to answer you.
All the aspects of that sign. MacArthur did a great job on this. From His commentary.
A SIGN OF CURSING
Some 15 years or so before Isaiah prophesied about the strange tongues from the lips of strangers, the northern kingdom of Israel had been conquered and taken captive by the Assyrians (in 722 BC) because of unbelief and apostasy. The prophet then warned the southern kingdom, Judah, that the same judgment awaited her at the hands of the Babylonians. The proud religious leaders of Judah would not listen to Isaiah. His teaching was too simple. He talked to them, they claimed, as if they were babies, "Those just weaned from milk" and "just taken from the breast." He taught them as if they were kindergartners: "Order on order, order on order, line on line, line on line, a little here, a little there" (
Isaiah 28:9-10). God had indeed spoken to them simply, in order that the least mature among them could understand and so that no Israelite would have an excuse for not knowing the Lord's will and promise. The essence of His promise was, "Here is rest, give rest to the weary," and "Here is repose"; yet Israel "would not listen" (v.12)
Isaiah 28:12.
About 800 years before Isaiah, God had warned Israel that "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" (
Deuteronomy 28:49). The strange language of their conquerors would be a sign of God's judgment. About 100 years after Isaiah, the Lord warned through Jeremiah, "Behold, I am bringing a nation against you from afar, O house of Israel,...a nation whose language you do not know, nor can you understand what they say" (
Jeremiah 5:15). The sign of judgment would be a language they could not understand.
When the apostles spoke at Pentecost and were heard in their own language by Jews from many countries (
Acts 2:7-11), those Jews should have known that Gods judgment was imminent. His judgment had fallen on rebellious Israel and then on rebellious Judah. How much more would it fall on those of His people who now had crucified the Son of God? In AD 70 that judgment fell, when Jerusalem was utterly destroyed by the Roman general Titus (later emperor). Over one million Jews were slaughtered; thousands more were taken captive; the Temple was plundered, desecrated, and then utterly destroyed; and the rest of the city was burned to the ground. One historian comments that Jerusalem had no history for 60 years. Just as Jesus had predicted when He wept over the city, "Your enemies will throw up a bank before you, and surround you, and hem you in on every side, and will level you to the ground and your children within you, and they will not leave in you one stone upon another, because you did not recognize the time of your visitation" (
Luke 19:44; cf.
Luke 21:20-24).
After the destruction of Jerusalem, and especially of the Temple, the reason for tongues ceased to exist. The judgment of which it was a sign had come. After the Pentecost manifestation of tongues, Peter, by implication, reminded his hearers of that judgment: " Therefor let all the house of Israel know for certain that God has made Him both Lord and Christ--this Jesus whom you crucified" (
Acts 2:36;cf.vv.
Acts 2:22-23).
A SIGN OF BLESSING
The second sign was a residual benefit of the first. The gift of tongues was a sign that God would no longer work through one nation, and favor one people. The church of Jesus Christ was for all peoples of all nations, a church in which there are many languages but no barriers. "There is neither Jew nor Greek, slave nor free man, there is neither male nor female; for you are all one in Christ Jesus" (
Galatians 3:28 ).
With great compassion and sorrow for his fellow Jews, Paul wrote in Romans, "But by their transgression salvation has come to the Gentiles, to make them jealous." But with a note of great hope he continued, "Now if their transgression be riches for the world and their failure be riches for the Gentiles, how much more will their fulfillment be!" (
Romans 11:11-12). A few verses later he explains more fully:" For I do not want you, brethren, to be uninformed of this mystery, lest you be wise in your own estimation, that a partial hardening has happened to Israel until the fullness of the Gentiles has come in; and thus all Israel will be saved; just as it is written" (vv.25-26)
Romans 11:25-26. The way would always be open for individual Jews to come into the kingdom, for the hardening was only partial, and one day the entire nation of Israel would be brought back to her Lord. The sign of tongues was repeated when the Gentiles were included in the church, as recorded in
Acts 10:44-46.
A SIGN OF AUTHORITY
Those who preached the judgment and promised the blessing were the apostles and prophets, whose authority was validated by "signs and wonders and miracles" (
2 Corinthians 12:12; cf.
Romans 15:19). Among the authenticating signs was the gift of tongues, in which Paul spoke "more than you all" (
1 Corinthians 14:18 ).
As a sign, the purpose of tongues ended when that to which it pointed ended. A person driving to Los Angeles may see the first mileage sign about 300 miles away. Later he sees one that reads "200 miles to Los Angeles," and then "50 miles," and then "10 miles." After he passes through the city, however, the mileage signs to Los Angeles cease. They have no further purpose, because that to which they pointed has been reached and passed. The gift of tongues was attached irretrievably to one point in history, and that point has long been passed.
It is interesting, and I believe highly significant, that no record is given is of a single word spoken in tongues or even interpreted. Every reference to tongues is general. They are always mentioned in relation to their purpose and significance, never in relation to their specific content. The messages given in tongues were not new revelations or new insights, but, as at Pentecost, simply unique expressions of old truths, "the mighty deeds of God" (
Acts 2:11). Though tongues could edify when interpreted, their purpose was not to teach, but to point, not to reveal God's truth but to validate the truth of his appointed spokesmen.
Since the destruction of Jerusalem in AD 70 there has been no purpose for the sign gift of tongues, because that to which it pointed has been reached and passed.. Israel has been set aside, the Gentiles have been brought in, and the apostles have given the faith once-for-all delivered to the saints. ---(MacArthur NT commentary)