Was the foreign tongue in Deuteronomy 28 an unknown tongue?
No. The foreign tongue in Deuteronomy 28 was not an unknown tongue; it was the actual language of an invading foreign nation. The Jews would hear it but not understand it, and Moses presented it as a warning that foreigners would occupy them.
Les explains that Deuteronomy is one of the five books of Moses and is directed to the children of Israel. In Deuteronomy 28:49, Moses writes that the Lord would bring a nation from far, as swift as an eagle, an enemy and invader, a nation whose tongue Israel would not understand. Les asks what tongue is meant and answers: their language. Whether Babylonians, Greeks, or Romans, a foreign nation would overrun and invade Israel, and the Jews would have to listen to them talking in their language while occupied. He stresses that it was not an unknown tongue, but a language the Jews could not understand, and it was a warning to the nation. Les then connects this to Paul in 1 Corinthians 14:21, where the Law says, “With men of other languages, and other lips, I will speak unto this people,” by occupying them, taking tribute, and putting them under servitude; yet they would not hear. Verse 22 adds that tongues, the ability to speak in languages, was for a sign to the Jew.
The LORD shall bring a nation against thee from far, from the end of the earth, as swift as the eagle flieth; a nation whose tongue thou shalt not understand;
More Questions
What does the law say about God speaking to Israel through men of other languages?
The Deuteronomy passage Paul quotes says that with men of other languages and other lips the Lord will speak to this people, and yet for all that they will not hear Him.