To perform the mercy Zacharias again points out the fountain from which redemption flowed, the mercy and gracious covenant of God. He assigns the reason why God was pleased to save his people. It was because, being mindful of his promise, he displayed his mercy. He is said to have remembrance of his covenant, because there might be some appearance of forgetfulness during that long delay, in which he allowed his people to languish under the weight of very heavy calamities. We must carefully attend to this order. First, God was moved by pure mercy to make a covenant with the fathers. Secondly, He has linked the salvation of men with his own word. [1] Thirdly, He has exhibited in Christ every blessing, so as to ratify all his promises: as, indeed, their truth is only confirmed to us when we see their fulfillment in Christ. Forgiveness of sins is promised in the covenant, but it is in the blood of Christ. Righteousness is promised, but it is offered through the atonement of Christ. Life is promised, but it must be sought only in the death and resurrection of Christ. This too is the reason why God commanded of old, that the book of the law should be sprinkled with the blood of the sacrifice, (Exodus 24:8; Hebrews 9:19, 20.) It is also worthy of notice, that Zacharias speaks of the mercy performed in his own age, as extending to the fathers who were dead, and who equally shared in its results. Hence it follows, that the grace and power of Christ are not confined by the narrow limits of this fading life, but are everlasting; that they are not terminated by the death of the flesh, for the soul survives the death of the body, and the destruction of the flesh is followed by the resurrection. As neither Abraham, nor any of the saints, could procure salvation to himself by his own power or merits, so to all believers, whether living or dead, the same salvation has been exhibited in Christ.

Footnotes

1 - "Il a lie le salut des hommes avec sa parole, comme dependant d'icelle." -- "He has bound the salvation of men with his word, as depending on it."

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.

His holy covenant - See the note on Luke 1:54.

To perform the mercy [promised] to our fathers, and (k) to remember his holy covenant;
(k) Declare indeed that he was mindful.

To perform the mercy promised to our fathers,.... By "mercy" is meant salvation by Christ, which springs from the mercy of God; the promise of which was an instance of mercy to the Jewish fathers under the Old Testament, and also the performance of it; for they were saved by the grace of our Lord Jesus, even as we: his blood was shed for the remission of sins that were past, and for the redemption of transgressions under the first Testament:
and to remember his holy covenant; which was made between him, and his Son from all eternity; and was, at various times, dispensed and manifested to the patriarchs, and eminent saints, as Adam, Noah, Abraham, &c. This is called an "holy" one; not only because it was made by, and between holy persons, and provided for the holiness of the people of God, both here, and hereafter; but because in the article of redemption and salvation by Christ, which is here more particularly regarded, care was taken to secure the glory of God's holiness and justice, as well as to display his grace and mercy. Now raising up, and sending Jesus a Saviour, showed, that God was mindful of this covenant, and therefore sent redemption to his people.

the mercy promised . . . his holy covenant . . .