Hebrews says that God spoke by the prophets (and presumably to the prophets)
“at many times and in many ways”. Among these methods were
visions, dreams and riddles.
The apostle Peter had one such experience on the housetop of Simon the tanner while waiting for a bite to eat and praying. Luke says, “He fell into a trance.” Peter heard a voice uttering actual words (as opposed to merely receiving an impression) and saw an accompanying vision, but the end result was perplexity, not sudden clarity.
Peter had indeed witnessed something spiritually
meaningful, but had yet to find the appropriate context in which to apply the instruction
he had received.