This was done thrice: and the vessel was received up again into heaven.
The vision repeated three times because the law ran so deep in Peter's mind that once would not shake his doubts free. God left him perplexed until the messengers arrived to explain it, which was fitting; and the sheet taken up to heaven certified him that this command came from God Himself, not from some earthly source.
AI summary
Peter clung to Jewish prejudice against Gentiles, thinking association with them brought ceremonial pollution. Scripture had plainly spoken of the Gentiles entering the church, Christ Himself had ordered it, yet Peter could not see it until God broke his bigotry with a vision.
AI summary
Commenting on Acts 10:9-18
The threefold repetition was not for mystical meaning but for Peter's confirmation, that he might be firmly assured. The vessel received into heaven signified that when the church, Jew and Gentile alike, is fully gathered, it will be taken up to its native place; it also certified to Peter that heaven itself ratified what he saw below, the taking away of the distinction between clean and unclean men.
AI summary