John Calvin on Acts 10:16

16. This was done thrice. The repetition of the vision served for the confirmation of Peter, lest any doubt “Vel anxietas vel scrupulus,” or anxiety or scruple, omitted. should remain in his mind. Whence we gather how deeply the observing of the law was rooted in his mind. And I know no reason why God left him in a dump, [perplexed,] until, by the event which followed, he might learn the cause of the vision, save only because being astonished he did not desire to know what this thing meant; although it was all in good time, that the messengers of Cornelius should come shortly after to interpret it. The vessel was at length taken up again into heaven, that Peter might be certified that this message came from heaven, [God.]

Acts 10:17-23

17. And as Peter doubted in himself what vision this should be which he had seen, behold, two men, sent from Cornelius, inquiring for Simon's house, stood at the door. 18. And when they had called, they asked whether Simon, surnamed Peter, did lodge there. 19. And as Peter thought upon the vision, the Spirit said to him, Behold, three men seek thee. 20. Arise, go down, and go with them, doubting nothing, because I have sent them. 21. And when Peter was come down unto the men which were sent from Cornelius unto him, he said, Behold, I am he whom ye seek. What is the cause wherefore ye come hither? 22. They said to him, Cornelius the captain, [centurion,] a just man, and one that feareth God, having testimony of all the nation of the Jews, was warned by an oracle by a holy angel, that he should call thee into his house, and should hear of thee words. 23. Furthermore, when he had called them in, he lodged them. “Accepit hospitio,” he hospitably entertained them.