Every man heard them speak, &c.— Some commentators of note, both antient and modern, have maintained that they spoke only one language, that is, Hebrew, or Syro-Chaldaic; but that the people heard them every one in their own language. This is really making the miracle consist in the hearing, and not in the speaking, and seems so groundless, that it does not need any laboured confutation. Our Saviour promised, Mark 16:17 that they should speak with new tongues, &c. And St. Luke here plainly asserts, Acts 2:4 that they did speak with other tongues, or in other languages. The same thing is either supposed or plainly asserted by St. Paul, 1 Corinthians 12:10; 1 Corinthians 12:28; 1 Corinthians 12:30 and 1 Corinthians 14:2-39. The mistake seems to have arisen from this and the 8th verse. But St. Luke did not intend to say, that any one of the apostles spoke more languages than one at a time, nor that they spoke one language, and the people heard one or many others; but his plain meaning is, that one of them spoke one language, and another another, and so on; and that different apostles addressed themselves to men of different nations at the same time; or that one apostle addressed himself to men of different nations one after another; by which means all the foreigners heard their own native language spoken distinctly and intelligibly; and not only the languages spoken, but the Christian doctrine also plainly delivered to them in their own language.
Related Commentaries of Acts 2:6
Acts 2:6
6 Now when this wasa noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language.