The Son of man shall send forth his angels, and they shall gather out of his kingdom - to which they never really belonged. They usurped their place and name and outward privileges; but “the ungodly shall not stand in the judgment, nor sinners [abide] in the congregation of the righteous” (Psa 1:5).
all things that offend - all those who have proved a stumbling-block to others
and them which do iniquity - The former class, as the worst, are mentioned first.