4. they . . . began to speak with . . . tongues, &c.--real, living languages, as is plain from what follows. The thing uttered, probably the same by all, was "the wonderful works of God," perhaps in the inspired words of the Old Testament evangelical hymns; though it is next to certain that the speakers themselves understood nothing of what they uttered (see on 1Co 14:1-25).

JFB.