Adam Clarke on Matthew 25:31

When the Son of man shall come - This must be understood of Christ's coming at the last day, to judge mankind: though all the preceding part of the chapter may be applied also to the destruction of Jerusalem.

Holy angels - The word αγιοι is omitted by many excellent manuscripts, versions, and fathers. Mill and Bengel approve of the omission, and Griesbach has left it out of the text. It is supposed by some that our Lord will have other angels (messengers) with him in that day, besides the holy ones. The evil angels may be in attendance to take, as their prey, those who shall be found on his left hand.

The throne of his glory - That glorious throne on which his glorified human nature is seated, at the right hand of the Father.