But if ye will not hearken unto me. Thus far a kind invitation has been set before the people in the shape of promises, in order that the observance of the Law might be rendered pleasant and agreeable; since, as we have already seen, our obedience is then only approved by God when we obey willingly. But, inasmuch as the sluggishness of our flesh has need of spurring, threatenings are also added to inspire terror, and at any rate to extort what ought to have been spontaneously performed. It may seem indeed that it may thus be inferred that threats are absurdly misplaced when applied to produce obedience to the Law, which ought to be voluntary; for he who is compelled by fear will never love God; and this is the main point in the Law. But what I have already shewn, will in some measure avail to solve this difficulty, viz., that the Law is deadly to transgressors, because it holds them tight under that condemnation from which they would wish to be released by vain presumptions; whilst threats are also useful to the children of God for a different purpose, both that they may be prepared to fear God heartily before they are regenerate, and also that, after their regeneration, their corrupt affections may be daily subdued. For although they sincerely desire to devote themselves altogether to God, still they have to contend continually with the remainders of their flesh. Thus, then, although the direct object of threats is to alarm the reprobate, still they likewise apply to believers, for the purpose of stimulating their sluggishness, inasmuch as they are not yet thoroughly regenerate, but still burdened with the remainders of sin.

But if ye will not hearken unto me,.... To his commandments, as the rule of their duty, and to his promises, as an encouragement to it, or to his prophets and ministers, explaining and enforcing his law, and exhorting to a cheerful obedience to it; so the Targum of Jonathan,"if ye will not hearken to the doctrine of them that teach my laws;''which was the sin of the Jews in later times, for which captivity and other calamities befell them, Jeremiah 7:25,
and will not do all these commandments; which he had delivered to them by Moses, whether moral, ceremonial, or judicial, recorded in this book and in the preceding; even all of them were to be respected, attended to, and performed, for the law curses everyone that does not do all things it requires, Galatians 3:10.

After God has set the blessing before them which would make them a happy people if they would be obedient, he here sets the curse before them, the evils which would make them miserable, if they were disobedient. Two things would bring ruin. 1. A contempt of God's commandments. They that reject the precept, will come at last to renounce the covenant. 2. A contempt of his corrections. If they will not learn obedience by the things they suffer, God himself would be against them; and this is the root and cause of all their misery. And also, The whole creation would be at war with them. All God's sore judgments would be sent against them. The threatenings here are very particular, they were prophecies, and He that foresaw all their rebellions, knew they would prove so. TEMPORAL judgments are threatened. Those who will not be parted from their sins by the commands of God, shall be parted from them by judgments. Those wedded to their lusts, will have enough of them. SPIRITUAL judgments are threatened, which should seize the mind. They should find no acceptance with God. A guilty conscience would be their continual terror. It is righteous with God to leave those to despair of pardon, who presume to sin; and it is owing to free grace, if we are not left to pine away in the iniquity we were born in, and have lived in.

A CURSE TO THE DISOBEDIENT. (Leviticus. 26:14-39)
But if ye will not hearken unto me, &c.--In proportion to the great and manifold privileges bestowed upon the Israelites would be the extent of their national criminality and the severity of their national punishments if they disobeyed.

The Curse for Contempt of the Law. - The following judgments are threatened, not for single breaches of the law, but for contempt of all the laws, amounting to inward contempt of the divine commandments and a breach of the covenant (Leviticus 26:14, Leviticus 26:15), - for presumptuous and obstinate rebellion, therefore, against God and His commandments. For this, severe judgments are announced, which were to be carried to their uttermost in a fourfold series, if the hardening were obstinately continued. If Israel acted in opposition to the Lord in the manner stated, He would act towards them as follows (Leviticus 26:16, Leviticus 26:17): He would appoint over them בּחלה terror, - a general notion, which is afterwards particularized as consisting of diseases, sowing without enjoying the fruit, defeat in war, and flight before their enemies. Two kinds of disease are mentioned by which life is destroyed: consumption and burning, i.e., burning fever, πυρετός, febris, which cause the eyes (the light of this life) to disappear, and the soul (the life itself) to pine away; whereas in Exodus 23:25; Exodus 15:26, preservation from diseases is promised for obedience to the law. Of these diseases, consumption is at present very rare in Palestine and Syria, though it occurs in more elevated regions; but burning fever is one of the standing diseases. To these there would be added the invasion of the land by enemies, so that they would labour in vain and sow their seed to no purpose, for their enemies would consume the produce, as actually was the case (e.g., Judges 6:3-4).