So Luke 24:16 Acts 9:7.
1. The Lord hereby shows his power over our senses, both outward and inward, in a signal, distinguishing way.
2. The weakness of mortals to see or hear heavenly things, unless he strengthen them.
3. Their fleeing and quaking argued the terror of God upon them; and thereby the truth and certainty of the vision, by hearing such a sound though they saw it not, Acts 9:7,8.