30. If his children shall forsake my law. The prophet proceeds yet farther, declaring, that although the posterity of David should fall into sin, yet God had promised to show himself merciful towards them, and that he would not punish their transgressions to the full extent of their desert. Moreover, to give the promise the greater efficacy, he always introduces God speaking, as if he presented to him a request corresponding with the precise words and express articles of his covenant.⁵ It was very necessary that this should be added; for so easily do we slide into evil, and so prone are we to continual falls, that unless God, in the exercise of his infinite mercy, pardoned us, there would not be a single article of his covenant which would continue steadfast. God, therefore, seeing that it could not be otherwise, but that the posterity of David, in so far as it depended upon themselves, would frequently fall from the covenant, by their own fault, has provided a remedy for such cases, in his pardoning grace.

Farther, as it is profitable for men to be subjected to divine correction, he does not promise that he will allow them to escape unpunished, which would be to encourage them in their sins; but he promises, that in his chastisements he will exercise a fatherly moderation, and will not execute vengeance upon them to the full extent which their sins deserve. It is also to be observed, that he promises pardon, not only for light offenses, but also for great and aggravated sins. It is not without cause that he uses these forms of expression, to forsake his law, to violate his statutes, not to walk in his judgments, and not to keep his commandments. Nor is it without cause that he uses the word transgression, or perfidiousness, and iniquity. We see, then, that the patience and lenity of God, by which he reconciles to himself the posterity of David, is extended even to sins of the most heinous and aggravated description.

This passage teaches us, that when God adopts men into his family, they do not forthwith completely lay aside the flesh with its corruptions, as is held by some enthusiasts, who dream, that as soon as we are grafted into the body of Christ, all the corruption that is in us must be destroyed. Would to God that we could all on a sudden change our nature, and thus exhibit that angelic perfection which they require! But as it is quite apparent, that we are far from such an attainment, so long as we carry about with us this tabernacle of flesh, let us bid adieu to that devilish figment, and let us all betake ourselves to the sanctuary of forgiveness, which is at all times open for us. God, unquestionably, is speaking of the household of his Church; and yet it is declared, with sufficient plainness, in the promise which he makes of pardoning their offenses, that they will transgress and be guilty of revolting from him.

To limit what is here said to the ancient people of Israel, is an exposition not only absurd, but altogether impious. In the first place, I take it as a settled point, which we have already had occasion often to consider, that this kingdom was erected to be a figure or shadow in which God might represent the Mediator to his Church: and this can be proved, not only from the testimony of Christ and the apostles, but it may also be clearly and indubitably deduced from the thing considered in itself. If we set Christ aside, where will we find that everlasting duration of the royal throne of which mention is here made? The second from David, in the order of succession, was despoiled of the greater part of the kingdom, so that out of twelve tribes he retained scarcely one tribe and a half. Afterwards, how many losses did this kingdom thus greatly reduced sustain, and by how many calamities was it defaced, until at length the king and the whole body of the people were dragged into captivity, with the utmost ignominy and reproach? And I pray you to consider where was the dignity of the throne, when the king, after his sons were put to death before his eyes, was himself treated as a criminal? (2 Kings 25:7.) The Jews were indeed afterwards permitted to dwell in their own country; but it was without the honor and title of a kingdom. Accordingly, Ezekiel (Ezekiel 21:27) declares thrice, that the crown shall be laid in the dust, "until he come whose right it is." The obvious conclusion then is, that perpetuity, as applied to this kingdom, can be verified in Christ alone. And, in fact, what access could the Jews of old time have had to God, or what access could we in the present day have to him, did not the Mediator come between us and him, to cause us find favor in his sight?

It now remains that we apply to ourselves the qualities of this kingdom of which we have been speaking. As its everlasting duration leads us to the hope of a blessed immortality, and its invincible strength inspires our minds with tranquillity, and prevents our faith from failing, notwithstanding all the efforts which Satan may put forth against us, and notwithstanding the numerous forms of death which may surround us; so the pardon which is here promised belongs to the spiritual kingdom of Christ: and it may be equally gathered from this passage, that the salvation of the Church depends solely upon the grace of God, and the truth of his promises. If it is objected, that those who are regenerated by the Spirit of God never totally fall away, because the incorruptible seed of the word abides in them, I grant that this is an important truth. It is not, however, a total apostasy which is here spoken of -- not such as implies the entire extinction of godliness in the individual chargeable with it. But it sometimes happens that the faithful cast off the yoke of God, and break forth into sin in such a manner, as that the fear of God seems to be extinguished in them; and such being the case, it was necessary that He should promise the pardon even of heinous sins, that they might not upon every fall be overwhelmed with despair. Thus David seemed, to outward appearance, to be wholly deprived of the Spirit of God, whom he prays to be restored to him. The reason why God leaves hope of pardon even for detestable and deadly transgressions is, that the enormity of our sins may not keep us back or hinder us from seeking reconciliation with him. From this, we are led to condemn the undue severity of the fathers, who scrupled to receive to repentance those who had fallen for the second or third time. Due care must indeed be taken lest, by too great forbearance, loose reins should be given to men to commit iniquity; but there is no less danger in an extreme degree of rigour. It is to be observed, that when God declares that he will show himself merciful towards sinners, who have violated his law, and broken his commandments, he purposely employs these odious terms to excite our hatred and detestation of sin, and not to entice us to the commission of it. Still, however, we must understand the passage as amounting to this, That although the faithful may not in every instance act in a manner worthy of the grace of God, and may therefore deserve to be rejected by him, yet he will be merciful to them, because remission of sins is an essential article promised in his covenant. And, indeed, as God in his law requires us to perform what exceeds our power, all that he promises in it is of no avail to us, to whom it can never be accomplished. Hence Paul, in Romans 4:14, affirms, "If the inheritance come by the law, faith is made void, and the promise made of none effect." To this also belong these words of Jeremiah,

"Behold, the days come, saith the Lord, that I will make a new covenant with the house of Israel, and with the house of Judah; not according to the covenant that I made with their fathers, in the day that I took them by the hand to bring them out of the land of Egypt; (which my covenant they brake, although I was an husband unto them, saith the Lord;) but this shall be the covenant that I will make with the house of Israel: After those days, saith the Lord, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. I will forgive their iniquity, and I will remember their sin no more." (Jeremiah 31:31-34)

Farther, since God does not adopt us as his children, to encourage us to take liberty to commit sin with the greater boldness, mention is here made at the same time of chastisement, by which he shows that he hates the sins of his children, and, warning them of what they have deserved in offending him, invites and exhorts them to repentance. This fatherly chastisement then, which operates as medicine, holds the medium between undue indulgence, which is an encouragement to sin, and extreme severity, which precipitates persons into destruction. Here the inspired writer adverts to the prophecy recorded in 2 Samuel 7:14, where God declares that in chastising his own people, he will proceed after the manner of men --

"If he commit iniquity, I will chasten him with the rod of men, and with the stripes of the children of men." (2 Samuel 7:14)

God there speaks of his chastising his people after the manner of men, either because the anger of a father in correcting his children proceeds from love, -- for he sees that otherwise he would fail in promoting their good; or it contains a contrast between God and men, implying, that in the task of chastising he will proceed with moderation and gentleness; for, were he to put forth his strength, he would immediately bring us to nothing, yea, he could do this simply by moving one of his fingers. The scope of both passages undoubtedly is, that whenever God punishes the sins of true believers, he will observe a wholesome moderation; and it is therefore our duty to take all the punishments which he inflicts upon us, as so many medicines. On this point, the Papists have egregiously blundered. Not understanding the true end and fruit of chastisements, they have imagined that God proceeds herein as if avenging himself upon sinners. Whence arose their satisfactions, and from these again proceeded pardons and indulgences, by which they endeavored to redeem themselves from the hand and vengeance of God.⁶ But God has nothing else in view than to correct the vices of his children, in order that, after having thoroughly purged them, he may restore them anew to his favor and friendship; according to the words of Paul in 1 Corinthians 11:33, which affirm that the faithful "are chastened of the Lord, that they should not be condemned with the world." For this reason, lest they should be overwhelmed with the weight of chastisement, he restrains his hand, and makes considerate allowance for their infirmity. Thus the promise is fulfilled, That he does not withdraw his loving-kindness from his people, even when he is angry with them; for, while he is correcting them for their profit and salvation, he does not cease to love them. It is, however, to be observed, that there is a change of person in the words. After it is said, If his children shall forsake my law, etc., it is at length subjoined, My loving-kindness or mercy will I not withdraw from Him. It ought surely to have been said, them instead of him, since it is children in the plural number who are before spoken of. But it is very probable that this form of expression is purposely employed to teach us that we are reconciled to God only through Christ; and that if we would expect to find mercy, we must seek for it from that source alone. What follows in the end of the verse, I will not suffer my faithfulness to fail, is more emphatic than if it had been said that God will be true to what he has said. It is possible that God's promise may fail of taking effect, and yet he may continue faithful. For example, the law is true and holy, and yet of what advantage is it to us that salvation is promised in the law, when no human being can ever obtain salvation by it? God then in this passage leads us farther; promising that his covenant shall be steadfast and effectual, not only because he will be faithful on his part, but also because he will keep his people from falling away through their own inconstancy.

34. My covenant will I not break. As the true knowledge of God's mercy can only be obtained from his word, he enjoins us to keep our eyes intently fixed upon his covenant. The more excellent and invaluable a blessing it is, "Never to be rejected after having been once adopted by him," the more difficult it is for us to believe its truth. And we know how many thoughts from time to time present themselves to our minds, tempting us to call it in question. That the faithful, therefore, may not harass themselves beyond measure in debating in their own minds whether or no they are in favor with God, they are enjoined to look to the covenant, and to embrace the salvation which is offered to them in it. God here commends to us his own faithfulness, that we may account his promise sufficient, and that we may not seek the certainty of our salvation any where else. He had said above, If the children of David break my statutes; and now, alluding to that breach, he declares that he will not requite them as they requite him, My covenant will I not break, implying, that although his people may not altogether act in a manner corresponding to their vocation, as they ought to do, he will not suffer his covenant to be broken and disannulled on account of their fault, because he will promptly and effectually prevent this in the way of blotting out their sins by a gratuitous pardon. He is still pursuing the illustration of the preceding proposition, I will not suffer my faithfulness to fail; promising not only to be faithful on his side, as we say, but also that what he has promised shall take full effect, in despite of all the impediments which men may cast in the way; for he will strive against their sins, that by means of them the fruit of his goodness may not be prevented from reaching them. When the Jews, by their ingratitude and treachery, revolted from him, the covenant was not disannulled, because it was founded upon the perfect immutability of his nature. And still, at the present day, when our sins mount even to the heavens, the goodness of God fails not to rise above them, since it is far above the heavens.

35. Once have I sworn by my holiness. God now confirms by an oath what he previously stated he had promised to David; from which it appears that it was not a matter of small importance; it being certain that God would not interpose his holy name in reference to what was of no consequence. It is a token of singular loving-kindness for him, upon seeing us prone to distrust, to provide a remedy for it so compassionately. We have, therefore, so much the less excuse if we do not embrace, with true and unwavering faith, his promise which is so strongly ratified, since in his deep interest about our salvation, he does not withhold his oath, that we may yield entire credence to his word. If we do not reckon his simple promise sufficient, he adds his oath, as it were, for a pledge. The adverb once,⁷ denotes that the oath is irrevocable, and that therefore we have not the least reason to be apprehensive of any inconstancy. He affirms that he sware by his holiness, because a greater than himself is not to be found, by whom he could swear. In swearing by Him, we constitute him our judge, and place him as sovereign over us, even as he is our sovereign by nature. It is a more emphatic manner of expression for him to say, by my holiness, than if he had said, by myself, not only because it magnifies and exalts his glory, but also because it is far more fitted for the confirmation of faith, calling back, as it does, the faithful to the earthly habitation which he had chosen for himself, that they might not think it necessary for them to seek him at a distance; for by the term holiness, I have no doubt, he means the sanctuary. And yet he swears by himself, and by nothing else; for, in naming the temple which he had appointed as his seat, he does not depart from himself; but, merely accommodating his language to our rude understandings, swears by his holiness which dwells visibly upon earth. With respect to the elliptical form of the oath, we have seen, in a previous psalm, that this was a manner of swearing quite common among the Hebrews. Thus they were warned that the name of God was not to be used without due consideration, lest, by using it rashly and irreverently, they should draw down upon themselves the Divine vengeance. The abrupt and suspended form of expression was, as it were, a bridle to restrain them, and give them opportunity for reflection. It is no uncommon thing for God to borrow something from the common custom of men.

36. His seed shall endure for ever. There now follows the promise that the right of sovereignty shall always remain with the posterity of David. These two things -- his offspring and his throne, are conjoined; and by these words the everlasting duration of the kingdom is promised, so that it should never pass to those who were of a strange and different race. The sun and the moon are produced as witnesses; for although they are creatures subject to corruption, they yet possess more stability than the earth or air; the elements, as we see, being subject to continual changes. As the whole of this lower world is subject to unceasing agitation and change, there is presented to us a more steadfast state of things in the sun and moon, that the kingdom of David might not be estimated according to the common order of nature. Since, however, this royal throne was shaken in the time of Rehoboam, as we have before had occasion to remark, and afterwards broken down and overthrown, it follows that this prophecy cannot be limited to David. For although at length the outward majesty of this kingdom was put an end to without hope of being re-established, the sun ceased not to shine by day, nor the moon by night. Accordingly, until we come to Christ, God might seem to be unfaithful to his promises. But in the branch which sprung from the root of Jesse, these words were fulfilled in their fullest sense.⁸