John Calvin Commentary Isaiah 65:5

"that say, Stand by thyself, come not near to me, for I am holier than thou. These are a smoke in my nose, a fire that burneth all the day." — Isaiah 65:5 (ASV)

Remain by thyself. He points out extreme impiety in the Jews, who obstinately and rebelliously opposed God’s worshippers, and refused to listen to any warnings. There is some hope of repentance, so long as we lend an ear to warnings and reproofs; but if we reject them, our case is undoubtedly hopeless.

Though the words are apparently obscure, their meaning amounts to this: hypocrites disdainfully and fiercely repel faithful advisers because they either make false claims to holiness or, on account of pride, do not allow themselves to be reproved. For hypocrisy is never free from supercilious disdain and haughtiness.

Let us not wonder, therefore, that those who are infected by this vice swell with insolent pretensions, boast of their virtue and holiness, and value themselves more highly than all others. Satan has blinded them to make an idle and ostentatious boast of what they call their devotions and to despise the word of God.

Commentators think that this is a general statement, which reproves the Jews for refusing to submit to the prophets. But it appears to me that we should take into account a circumstance to which they do not give sufficient weight: this verse is in close and immediate connection with the preceding verses. It contains a sharp reproof of the Jews, not only for revolting from the true worship but also for obstinately following their own inventions, so that they turn with disdain from everyone who did not flatter them. For that phrase, “Remain with thyself,” means nothing else than “Away with thee!” as if they declared that they would have nothing to do with honest instructors.