III. Lastly, in this passage we find another external proof of the Spirit's presence in the miraculous gift of tongues. That gift indicated to the Apostles and to all ages the tongue as the instrument by which the gospel was to be propagated, as the symbol fire indicated the cleansing and purifying effects of the Spirit.[49] The gift of tongues is one that has ever excited much speculation, and specially so during the present century, when, as some will remember, an extraordinary attempt to revive them was made, some sixty years ago, by the followers of the celebrated Edward Irving. Devout students of Scripture have loved to trace in this incident at Pentecost, at the very foundation of the new dispensation, a reversal of that confusion of tongues which happened at Babel, and have seen in it the removal of "the covering cast over all peoples, and the veil that is spread over all nations."[50] The precise character of the gift of tongues has of late years exercised many minds, and different explanations have been offered of the phenomena. Some have viewed it as a miracle of hearing, not of speaking, and maintained that the Apostles did not speak different languages at all, but that they all spake the one Hebrew tongue, while the Jews of the various nationalities then assembled miraculously heard the gospel in their own language. [49] Lightfoot, _Horæ Hebraicæ_, Acts, chap. ii., ver. 3, notes that "there is a form of prayer in the Jewish writings which was used on the solemn fast of the ninth month Ab, one clause of which illustrates the Divine symbol, 'Have mercy, O God, upon the city that mourneth, that is trodden down and desolate, because Thou didst lay it waste by fire, and by fire wilt build it up again.'" [50] Isa. xxv. 7. See Lightfoot, _Horæ Heb._, on Acts ii.