William Burkitt on Acts 9:7

Observe here, The testimony or witnesses of Saul's conversion, to writ, the men that journeyed with him; it is probable that he had a considerable number of officers with him, to bring both men and women that professed Christianity bound to Jerusalem. These saw the light shining and heard a confused noise like thunder, but they saw not Christ himself, as he did, nor heard the articulate voice of Christ that he heard, which spake so powerfully, so convincingly, and so convertingly to his soul.

Lord, how many are there that come under thine ordinances, who hear only (like Saul's companions) a confused noise and empty sound! They do not hear the distinct voice of Christ speaking to their hearts with a strong hand, inwardly and effectually, and so remanin under the power of unbelief, in an unconverted state.