For we know him that hath said, Vengeance belongeth unto me, I will recompense, saith the Lord. And again, The Lord shall judge his people. Vengeance belongeth unto me - This is the saying of God, Deuteronomy 32:35, in reference to the idolatrous Gentiles, who were the enemies of his people; and is here with propriety applied to the above apostates, who, being enemies to God's ordinances, and Christ's ministry and merits, must also be enemies to Christ's people; and labor for the destruction of them, and the cause in which they are engaged.
The Lord shall judge his people - That is, he shall execute judgment for them; for this is evidently the sense in which the word is used in the place from which the apostle quotes, Deuteronomy 32:36 : For the Lord shall judge his people, and repent himself for his servants, when he seeth that their power is gone. So God will avenge and vindicate the cause of Christianity by destroying its enemies, as he did in the case of the Jewish people, whom he destroyed from being a nation, and made them a proverb of reproach and monuments of his wrathful indignation to the present day.