And the other Jews - That is, those who had been converted to Christianity. It is probable that they were induced to do it by the example of Peter, as they would naturally regard him as a leader.
Dissembled likewise with him - Dissembled or concealed their true sentiments. That is, they attempted to conceal from those who had come down from James the fact that they had been in the habit of associating with the Gentiles, and of eating with them. From this it would appear that they intended to conceal this wholly from them, and that they withdrew from the Gentiles before anything had been said to them by those who came down from James.
Insomuch that Barnabas also was carried away - Concerning Barnabas, see the note at Acts 4:36. Barnabas was the intimate friend of Paul. He had been associated with him in very important labors; and the fact, therefore, that the conduct of Peter was exciting so unhappy an influence as even to lead so worthy and good a man as he was into hypocrisy and error, made it the more proper that Paul should publicly notice and reprove the conduct of Peter. It could not but be a painful duty, but the welfare of the church and the cause of religion demanded it, and Paul did not shrink from what was so obvious a duty.

And the other Jews dissembled likewise - That is: Those who were converted to Christianity from among the Jews, and who had also been convinced that the obligation of the Jewish ritual had ceased, seeing Peter act this part, and also fearing them that were of the circumcision, they separated themselves from the converted Gentiles, and acted so as to convince the Jews that they still believed the law to be of moral obligation; and so powerful was the torrent of such an example, that the gentle, loving-hearted Barnabas was carried away by their dissimulation, αυτων τῃ ὑποκρισει, with their hypocrisy - feigning to be what they really were not.

And the other Jews dissembled likewise with him; insomuch that Barnabas also was (k) carried away with their dissimulation.
(k) By example rather than by judgment.

And the other Jews dissembled likewise with him,.... Not the men that came from James, for they never acted otherwise, and therefore could not be said to dissemble; but the Jews that were members of this church at Antioch from the beginning; or who came along with Paul and Barnabas, and stayed with them there; see Acts 15:35 and who before had ate with the Gentiles, as Peter; but being under the same fear he was, and influenced by his example, concealed their true sentiments, and acted the very reverse of them, and of their former conduct:
insomuch that Barnabas also was carried away with their dissimulation; so good a man as he was, full of faith, and of the Holy Ghost; who had been a companion of the Apostle Paul's in his travels among the Gentiles, had greatly assisted him in preaching the Gospel to them, was a messenger with him at the council in Jerusalem, heard the debates of that assembly, and the issue of them, returned with him to Antioch, and was one with him both in principle and practice; and yet so forcible was the example of Peter, and the other Jews, that, as with a mighty torrent, he was carried away with it, and not able to withstand it; such is the force of example in men who are had in great veneration and esteem: wherefore it becomes all persons, particularly magistrates, masters of families, and ministers of the Gospel, to be careful what examples they set, since men both of grace and sense are much influenced by them.

the other--Greek, "the rest."
Jews--Jewish Christians.
dissembled likewise--Greek, "joined in hypocrisy," namely, in living as though the law were necessary to justification, through fear of man, though they knew from God their Christian liberty of eating with Gentiles, and had availed themselves of it already (Acts 11:2-17). The case was distinct from that in 1Co. 8:1-10:33; Romans. 14:1-23. It was not a question of liberty, and of bearing with others' infirmities, but one affecting the essence of the Gospel, whether the Gentiles are to be virtually "compelled to live as do the Jews," in order to be justified (Galatians 2:14).
Barnabas also--"Even Barnabas": one least likely to be led into such an error, being with Paul in first preaching to the idolatrous Gentiles: showing the power of bad example and numbers. In Antioch, the capital of Gentile Christianity and the central point of Christian missions, the controversy first arose, and in the same spot it now broke out afresh; and here Paul had first to encounter the party that afterwards persecuted him in every scene of his labors (Acts 15:30-35).

And the other believing Jews - Who were at Antioch. Dissembled with him, so that even Barnabas was carried away with their dissimulation - Was borne away, as with a torrent, into the same ill practice.