Psalms 103:17,18 - Joseph Benson’s Commentary on the Old and New Testaments

But the mercy of the Lord is from everlasting, &c. But though we quickly decay and perish, yet God's mercy to us doth not die with us, but, as it was from eternity exercised in gracious purposes, so it will be continued unto eternity in that future and endless life which is before us; upon them that fear him That is, upon them that are truly religious: see above on Psalms 103:11. And his righteousness unto children's children Either his faithfulness, or his benignity, the word being frequently used in both these senses, as has been shown before. But it is here called righteousness, to intimate that God's kindness to the posterity of his people is not only an act of his goodness, but also a discharge of the obligation under which he had laid himself to them, as elsewhere, so especially Exodus 20:6, to which this place seems to relate. To such as keep his covenant To them that, through his grace, perform the condition of God's covenant, that sincerely love and obey him. Such restrictions are often added, as, in the general, to overthrow the presumptuous hopes of ungodly men, so particularly to admonish the Israelites not to rest too much on the privileges of their parents, or the covenant made with them, nor to expect any benefit by it but upon condition of their continuance in God's covenant. And to those that remember his commandments That have them much in their thoughts, and practise them in the course of their lives.