John Chrysostom — on Acts 2:3 (Homily on Acts 4)

“"And there appeared unto them," it says, "cloven tongues like as of fire." Observe how it is always, "like as;" and rightly: that you may have no gross sensible notions of the Spirit. Also, "as it were of a blast:" therefore it was not a wind. "Like as of fire." For when the Spirit was to be made known to John, then it came upon the head of Christ as in the form of a dove: but now, when a whole multitude was to be converted, it is "like as of fire. And it sat upon each of them." This means, that it remained and rested upon them. For the sitting is significant of settledness and continuance.”