Albert Barnes Commentary Acts 10:14

"But Peter said, Not so, Lord; for I have never eaten anything that is common and unclean." — Acts 10:14 (ASV)

I have never eaten, etc. In the Old Testament, God had made a distinction between clean and unclean animals. See Leviticus 11:2-27; Deuteronomy 14:3–20. This law remained in the Scriptures, and Peter pleaded that he had never violated it, implying that he could not now violate it; as it was a law of God, and as it was unrepealed, he did not dare to act in a different manner from what it required.

Between that law and the command which he now received in the vision, there was an apparent variation; and Peter naturally referred to the well-known and admitted written law. One design of the vision was to show him that this law was now to pass away.

That is common. This word properly denotes that which pertains to all. Among the Jews, however, who were bound by special laws and prohibited from many things freely indulged in by other nations, the word common came to be opposed to the word sacred. It also came to denote that which was in common use among the heathens—hence, that which was profane or polluted. Here it means the same as profane or forbidden.

Unclean. Ceremonially unclean; that is, that which is forbidden by the ceremonial law of Moses.