John Calvin Commentary Acts 10:28

"and he said unto them, Ye yourselves know how it is an unlawful thing for a man that is a Jew to join himself or come unto one of another nation; and [yet] unto me hath God showed that I should not call any man common or unclean:" — Acts 10:28 (ASV)

You know that it is not lawful. This seems to be no friendly preface, and one that may rather harden than win their hearts, when they hear that they are considered so unclean that by their familiarity and interaction they pollute the saints; which must indeed be a great reproach to them.

But it was necessary for Peter to speak this way, lest they suspect that he had an evil conscience because, contrary to the custom handed down by the fathers, he came. But when he affirms that he was sent by God, all such suspicion is removed and cleared.

Moreover, by these words, he mitigates very well the offense that lingered in their minds because of an old grudge between the Jews and the Gentiles, so that he could not have begun his speech in any better way. For he declares that those who were previously unclean are now clean, so that they now have mutual fellowship with the saints.

Furthermore, regarding his statement that it was wickedness for the Jews to associate with Gentiles, we must know that this came not so much from the Law as from the tradition of the fathers. God had indeed forbidden that they should entangle themselves with marriages or covenants (Deuteronomy 7:3); they were never forbidden to eat with them or to engage in the common affairs of life.

But lest that familiarity entice them into what was forbidden, they observed the custom handed down by the fathers, so that they did not associate with one another. It is pointless to dispute here whether that tradition bound men’s consciences, for Peter does not teach what is lawful according to God, but what was commonly practiced.

No man. He makes the sum and purpose of the vision clearer when he applies to men what was spoken of foods. And when he says that no man is unclean, this should not be understood as applying to every individual person. For it is certain that all unbelievers are polluted with an unclean conscience, so that they pollute those things which are otherwise pure, even when they merely touch them.

Paul also says that their children remain unclean until they are cleansed by faith. Finally, if faith alone cleanses and purifies the hearts of men, unbelief makes them profane.

But Peter compares the Jews and the Gentiles together in this passage. And because the wall of separation has been pulled down, and the covenant of life is now common to them both equally, he says that those who are made partakers of God’s adoption are not to be considered aliens.