{Parting asunder} (diamerizomenai). Present middle (or
passive) participle of diameriz(935c), old verb, to cleave asunder,
to cut in pieces as a butcher does meat (aorist passive in  Lu
11:17f. ). So middle here would mean, parting themselves asunder
or distributing themselves. The passive voice would be "being
distributed." The middle is probably correct and means that "the
fire-like appearance presented itself at first, as it were, in a
single body, and then suddenly parted in this direction and that;
so that a portion of it rested on each of those present"
(Hackett). The idea is not that each tongue was cloven, but each
separate tongue looked like fire, not real fire, but looking like
(h(9373)ei, as if) fire. The audible sign is followed by a visible
one (Knowling). "Fire had always been, with the Jews, the symbol
of the Divine presence (cf.  Ex 3:2  De 5:4 ). No symbol could be
more fitting to express the Spirit's purifying energy and
refining energy" (Furneaux). The Baptist had predicted a
baptizing by the Messiah in the Holy Spirit and in fire ( Mt
3:11 ). {It sat} (ekathisen). Singular verb here, though plural
(9370)th(8873)an with tongues (gl(9373)sai). A tongue that looked like
fire sat upon each one.