Why did Peter say he had never eaten anything that was common or unclean?
Peter made that statement because he remained a law-keeping Jew. As a law-keeping Jew, he had not eaten anything common or unclean. This conflicted with the sovereign intervention that brought him to Cornelius's house, where God was forcing the issue and preparing to deal with a Gentile.
Les explains that Peter and six other believing Jews had, by sovereign intervention, made their way up to Caesarea to the house of a Roman army officer and all his relatives and friends. Peter first said he had never eaten anything common or unclean because he was still a law-keeping Jew. At the threshold of Cornelius's house he was almost shaking in his boots, but knowing God was forcing the issue, he went in. He also acknowledged it was unlawful for him, a Jew, to keep company with someone of another nation. After Cornelius rehearsed all that had happened to him, Peter gained confidence that God was evidently going to deal with this Gentile, recognizing God was doing something totally different.
But Peter said, Not so, Lord; for I have never eaten any thing that is common or unclean.
More Questions
What does Peter's reaction to the vision of unclean animals show about his relationship to the law?
Peter's vision in Acts 10:14 showed him a sheet full of unclean animals according to the Jewish diet, and his reaction demonstrates he had not been set free from the law.
Why did Peter refuse to eat the unclean animals in his vision in Acts 10?
Peter refused the Lord's command to 'rise, kill and eat' the unclean creatures in the sheet vision because he was a Law-keeping Jew and the food had to be kosher or he would not eat it.