What does Acts 11:10 mean?

Peter is in Jerusalem, explaining to the church leaders why he ate with a houseful of Gentiles. He begins by describing a vision God gave him. He had been on a rooftop of the home of a friend, praying. He fell into a trance and saw a sheet lowering from heaven. On the sheet were all kinds of animals. God's voice told him to kill and eat; Peter refused as some of the animals were not allowed as food according to the Mosaic law. God responded that He had made them clean and His judgments were not Peter's to question (Acts 10:9–16). Perhaps in an homage to Peter's three denials of Jesus (Mark 14:66–72) and the three times Jesus asked Peter if he loved Him (John 21:15–19), the vision occurs three times before the sheet is lifted to heaven (Acts 10:16).

That the sheet came from heaven and returned to heaven may be significant. The lesson Peter is learning is very difficult for a devout Jew—to set aside an important section of the Mosaic law (Leviticus 11). Peter still considers himself a Jew, albeit one who has met the Messiah. That the food comes from and returns to heaven may give evidence that God is providing it. Peter quickly realizes that while God is declaring all foods clean, He's also declaring all people clean: devout Jews, as well as Gentiles who accept Jesus as their Savior. After all, the Mosaic law never saved, it just pointed to the fact that we all need a Savior (Hebrews 9:13–15).