3. Though God will afflict them, yet he will make their afflictions to work for the good of their souls, and correct them as the father does the child, to drive out the foolishness that is bound up in their hearts (v. 9): By this therefore shall the iniquity of Jacob be purged. This is the design of the affliction, to this it is adapted as a proper means, and, by the grace of God working with it, it shall have this blessed effect. It shall mortify the habits of sin; by this those defilements of the soul shall be purged away. It shall break them off from the practice of sin: This is all the fruit, this is it that God intends, this is all the harm it will do them, to take away their sin, than which they could not have a greater kindness done them, though it be at the expense of an affliction. Therefore, because the affliction is mitigated and moderated, and the rough wind stayed, therefore we may conclude that he designs their reformation, not their destruction; and, because he deals thus gently with us, we should therefore study to answer his ends in afflicting us. The particular sin which the affliction was intended to cure them of was the sin of idolatry, the sin which did most easily beset that people and to which they were strangely addicted. Ephraim is joined to idols. But by the captivity in Babylon they were not only weaned from this sin, but set against it. Ephraim shall say, What have I do to any more with idols? Jacob has his sin taken away, his beloved sin, when he makes all the stones of the altar, of his idolatrous altar, the stones of which were precious and sacred to him, as chalk-stones that are beaten asunder; he not only has them in contempt, and values them no more than chalk-stones, but he conceives an indignation at them, and, in a holy revenge, beats them asunder as easily as chalk-stones are broken to pieces. The groves and the images shall not stand before this penitent, but they shall be thrown down too, never to be set up again. This was according to the law for the demolishing and destroying of all the monuments of idolatry (Deut. vii. 5); and according to this promise, since the captivity in Babylon, no people in the world have such a rooted aversion to idols and idolatry as the people of the Jews. Note, The design of affliction is to separate between us and sin, especially that which has been our own iniquity; and then it appears that the affliction has done us good when we keep at a distance from the occasions of sin, and use all needful precaution that we may not only not relapse into it, but not so much as be tempted to it, Ps. cxix. 67.