Forsaketh not his saints - חטידיו את eth chasidaiv, his merciful or compassionate ones; those who, through love to him and all mankind, are ever ready to give of their substance to the poor.
But the seed of the wicked shall be cut off - The children who follow the wicked steps of wicked parents shall, like their parents, be cut off. God's judgments descend to posterity, as well as his mercies.
For the Lord loveth judgment - That is, God loves that which is right; he loves to do right. The idea is, that such a recompense as is here adverted to - that on the one hand, in rewarding with prosperity a pure and upright life - and that, on the other, in cutting off the wicked - is right and proper in itself; and that as God loves to do right, these consequences respectively may be expected to follow in regard to the righteous and the wicked. Compare Psalm 11:7.
And forsaketh not his saints - He manifests his sense of that which is right, by not forsaking His saints.
They are preserved forever - They are ever under his paternal eye, and he will keep them. It will be literally true that they will be preserved “forever,” that they will never be suffered to perish.