Suddenly, the apostles themselves not expecting it, there came a sound from heaven as of a rushing mighty wind; to prepare them to attend the more unto what they should hear and see afterwards; also to signify the unexpected and powerful progress which the gospel should have: it may be, to cause the greater concourse to that place, it being a usual manner; and God would make this miracle more public. It filled all the house; to show that the Spirit should be bestowed on them that were met there, and on all the church throughout the world.
Related Commentaries of Acts 2:2
Acts 2:2
2 And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.