To perform the mercy - To show the mercy promised. The expression in the “original” is, “To make mercy with our fathers” - that is, to show kindness to our fathers; and the propriety of it is founded on the fact that mercy to “children” is regarded as kindness to the “parent.” Blessing the “children” was blessing the “nation;” was fulfilling the promises made to the fathers, and “showing” that he regarded them in mercy.
His holy covenant - The word “covenant” means compact or agreement. This is in use among people. It implies equality in the parties; freedom from constraint; freedom from previous obligation to do the thing now covenanted; and freedom from obligation to enter into a compact, unless a man chooses so to do. Such a transaction evidently can never take place between man and God, for they are not equal. Man is not at liberty to “decline” what God proposes, and he is under obligation to do “all” that God commands. When the word “covenant,” therefore, is used in the Bible, it means sometimes a “command;” Sometimes a “promise;” sometimes a “regular law” - as “the covenant of the day and night;” and sometimes the way in which God dispenses mercy - that is, by the old and new covenants. In the place before us it means “the promise” made to Abraham, as the following verses clearly show.