This verse may be viewed as containing a simple promise; but I prefer to regard it as including what is between an exhortation and a promise. The first thing is, that God reminds the Jews for what purpose he would send John, even to turn the hearts of men and to restore them to a holy unity of faith. It must therefore be noticed, that not only the Redeemer would come, but that after some intermission, as it has been said, had taken place, the doctrine of salvation would again have its own course, and would be commenced by John.

Yet the Prophet seems here to concede to men more than what is right, for the turning of the heart is God’s peculiar work, and still more, it is more peculiarly his than his other works; and if no one can change a hair on the head of his brother, how can he renew his heart, so as to make him a new man? It is at the same time of more consequence to be regenerated than to be created and to be made only the inhabitants of this world. John then seems to be here too highly extolled, when the turning of the heart is ascribed to him. The solution of this difficulty may be easily given: when God thus speaks highly of his ministers, the power of his Spirit is not excluded; and he shows how great is the power of truth when he works through it by the secret influence of his Spirit. God sometimes connects himself with his servants, and sometimes separates himself from them: when he connects himself with them, he transfers to them what never ceases to dwell in him; for he never resigns to them his own office, but makes them partakers of it only. And this is the import of such expressions as these,

“Whose sins ye remit, they are remitted: whatsoever ye shall bind on earth, shall be bound in heaven,” (John 20:23;)

or when Paul says, that he had begotten the Corinthians, (1 Corinthians 2:15,) he did not claim for himself what he knew only belonged to God, but rather extolled the favor of God as manifested in his ministry, according to what he declares in another place,

“Not I, but the grace of God which was with me.”
(1 Corinthians 15:10.)

But when God separates himself from his ministers, nothing remains in them: “He who plants is nothing,” says Paul in another place,

“And he who waters is nothing, but God who gives the increase.” (1 Corinthians 3:7.)

When then is it that teachers are co-workers with God? Even when God, ruling them by his Spirit, at the same time blesses their labor, so that it brings forth its fruit.

We now then see that this mode of speaking derogates nothing from God, that is, when the minister is said to turn the hearts of men; for as he implants nothing by his own influence, so God supplies what is necessary that he may fulfill his office.

By saying that he would turn the hearts of fathers to sons and of sons to fathers, ²⁷⁷²⁷⁷     Newcome’s version is different,
   That he may convert the heart of the fathers together with the children, And the heart of the children together with their fathers.
   This is inconsistent with the passage partially quoted in Luke 1:17, and also with the Septuagint version, which is as follows —
   Who shall restore the heart of the father to the son, And the heart of a man to his neighbor.
   Internal discord was a prevailing evil among the Jews. What is here promised is union and concord as the effect of the ministry of the second Elijah; but it is announced in terms suitable to a single family. — Ed.
     he points out not a simple union or consent, for men often unite together, and yet God reprobates and hates their union; but the Prophet here has in view the origin of the people, even Abraham and other holy patriarchs. Had he spoken of the Egyptians or the Assyrians, or some other nations, this turning would not have been so wonderful; but when he speaks of the holy and chosen race, it is no wonder that he mentions it as an instance of the ineffable kindness of God, that they were all to be gathered and restored from discord to unity, so as to become united in one faith.

Since their mutual consent is the subject, we must come to the fountain; for Malachi takes it for granted, that there was formerly true religion in that people, that the true worship of God prevailed among them, and that they were bound together by a sacred bond; but since in course of time various notions rose among them, yea, monstrous dotages, since sincerity had become wholly corrupted, he now recalls them to their first condition, so that sons might unite in sentiment with their fathers, and fathers also with their sons, and become one in that faith which had been delivered in the law.

Were any to object and say, that it was not reasonable that fathers should join themselves to their apostate sons, for this would be to approve of their defection, I answer, that there have been some converted young men who have shown the right way to their fathers, and have carried light before them. We indeed know that old men, as their are morose, not only reject what they hear from the young, but are rendered more obstinate, because they are ashamed to learn. Such a dispute the Prophet bids to be dismissed, so that all might in their heart think only the same thing in the Lord.

Lest I come and smite the land with a curse. Here again the Prophet threatens the Jews, and indeed vehemently. He was constrained, as we have said, by necessity, for the torpor of that people was very great, and many of them were hardened in their perverseness. This is the reason why God now declares, that the Jews would not escape unpunished for despising the coming of Christ. And we are at the same time reminded how abominable in the sight of God is the ingratitude of not receiving his Son whom he sends to us. If we wish to derive benefit from what the Prophet teaches us, we ought especially to welcome Christ, while he so kindly calls us, yea, allures us to himself. But if the sloth of our flesh keeps us back, let even this threatening stimulate us; and as we learn that the sin of not embracing Christ when he offers himself to us, shall not go unpunished, let us struggle against our tardiness. At all events, let us take heed to kiss the Son, as in Psalm 2:12, we are exhorted to do.