The next day, as they were on their journey and coming near the city, Peter went up on the housetop to pray, about the sixth hour. And he became hungry and desired something to eat; but while they were preparing it, he fell into a trance and saw the heaven opened, and something descending, like a great sheet, let down by four corners upon the earth. In it were all kinds of animals and reptiles and birds of the air. And there came a voice to him, “Rise, Peter; kill and eat.” But Peter said, “No, Lord; for I have never eaten anything that is common or unclean.” And the voice came to him again a second time, “What God has cleansed, you must not call common.” This happened three times, and the thing was taken up at once to heaven.
–Acts 10:9-16