John Gills Exposition of the Bible Commentary - Isaiah 66:17
They that sanctify themselves ,.... This is a description of the enemies of the Lord, and of his people, who shall be slain at this time; not who are sanctified by the Spirit and grace of God, but who sanctify themselves, pretend to make themselves holy, and give out that they are holier than others; professing great outward sanctity, as the Papists do, but destitute of real inward holiness: or, "that prepare themselves", as the Targum; to go and worship such an idol, on such a day, as... read more
Matthew Henry's Complete Commentary - Isaiah 66:15-24
These verses, like the pillar of cloud and fire, have a dark side towards the enemies of God's kingdom and all that are rebels against his crown, and a bright side towards his faithful loyal subjects. Probably they refer to the Jews in captivity in Babylon, of whom some are said to have been sent thither for their hurt, and with them God here threatens to proceed in his controversy; they hated to be reformed, and therefore should be ruined by the calamity (Jer. 24:9); others were sent thither... read more