John Gill Commentary Acts 10:16

"And this was done thrice: and straightway the vessel was received up into heaven." — Acts 10:16 (ASV)

This was done thrice That is, either the voice spoke the same words three times, or the sheet was let down three times; and it may be both; it may be, that every time the voice was spoken, the sheet was let down: this was done, not with respect to any mystical meaning in the number three, but for the confirmation of Peter, that he might be the more firmly assured of the truth of the things represented unto him:

and the vessel was received up again into heaven to denote, that when the general assembly and church of the firstborn, whose names are written in heaven, whether Jews or Gentiles, are all gathered in, by the preaching of the Gospel to them, they will be taken up to heaven, their original and native place, and be for ever with the Lord; as well as to certify to Peter, that what was now shown him on earth, concerning the taking away the distinction of men and meats, was ratified in heaven.