John Chrysostom

"But Peter said, Not so, Lord; for I have never eaten anything that is common or unclean." This was a thing altogether offensive to them: observe then what is providentially managed. He himself also says, "I have never eaten": not being himself afraid - far be the thought from us - but it is so contrived by the Spirit, in order that he may have it to say in answer to those accusing him, that he did object: for it was altogether necessary for them to observe the Law. …

Homily on Acts 22 ↗

Clement of Alexandria

Peter abstained from swine; "but a trance fell on him," as is written in the Acts of the Apostles, "and he saw heaven opened, and a vessel let down on the earth by the four corners, and all the four-footed beasts and creeping things of the earth and the fowls of heaven in it; and there came a voice to him, Rise, and slay, and eat. And Peter said, Not so, Lord, for I have never eaten what is common or unclean. …

The Instructor Book 2 ↗

Bede

Because I have never eaten anything common and unclean. The people of the Jews, boasting themselves as part of God, call common foods those which all men use. For example, pork, oysters, hares, and such animals which do not split the hoof, nor chew the cud, nor have scales among fish. But unclean foods are said to be the flesh of beasts or reptiles, which are not edible by any mortals.

Commentary on Acts ↗