And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. A sound from heaven - Probably thunder is meant, which is the harbinger of the Divine presence.
Rushing mighty wind - The passage of a large portion of electrical fluid over that place would not only occasion the sound, or thunder, but also the rushing mighty wind; as the air would rush suddenly and strongly into the vacuum occasioned by the rarefaction of the atmosphere in that place, through the sudden passage of the electrical fluid; and the wind would follow the direction of the fire. There is a good deal of similarity between this account and that of the appearance of God to Elijah, 1 Kings 19:11, 1 Kings 19:12, where the strong wind, the earthquake, and the fire, were harbingers of the Almighty's presence, and prepared the heart of Elijah to hear the small still voice; so, this sound, and the mighty rushing wind, prepared the apostles to receive the influences and gifts of the Holy Spirit. In both cases, the sound, strong wind, and fire, although natural agents, were supernaturally employed. See the note on Acts 9:7.