Albert Barnes' Notes on the Whole Bible - Psalms 18:25
With the merciful - From the particular statement respecting the divine dealings with himself the psalmist now passes to a general statement (suggested by what God had done for him) in regard to the general principles of the divine administration. That general statement is, that God deals with men according to their character; or, that he will adapt his providential dealings to the conduct of men. They will find him to be such toward them as they have shown themselves to be toward him. The word... read more
The Pulpit Commentary - Psalms 18:25-28
A short didactic digression is here interposed, extending the principles on which God has dealt with David and his enemies, to mankind generally ( Psalms 18:25-27 ); after which a return is made to Go&'s special dealings with David ( Psalms 18:28 ). read more