Matthew Poole and continuators on Psalms 103:18

18 To such as keep his covenant , and to those that remember his commandments to do them .

To them that perform the conditions of Gods Covenant; that sincerely love and obey him. Such restrictions are oft added as in the general to overthrow the presumptuous hopes of ungodly men, so particularly to admonish the Israelites not to rest too much upon the priviledges of their Parents or the Covenant made with them, nor to expect any benefit by it, but upon condition of their continuance in Gods Covenant.

That have them much in their thoughts and practise them in the course of their lives.

Marginal references: Deut. 7. 9.