Here is, I. A very strange supposition, v. 1, 2. 1. It is strange that there should arise any among themselves, especially any pretending to vision and prophecy, who should instigate them to go and serve other gods. Was it possible that any who had so much knowledge of the methods of divine revelation as to be able to personate a prophet should yet have so little knowledge of the divine nature and will as to go himself and entice his neighbours after other gods? Could an Israelite ever be guilty of such impiety? Could a man of sense ever be guilty of such absurdity? We see it in our own day, and therefore may think it the less strange; multitudes that profess both learning and religion yet exciting both themselves and others, not only to worship God by images, but to give divine honour to saints and angels, which is no better than going after other gods to serve them; such is the power of strong delusions. 2. It is yet more strange that the sign or wonder given for the confirmation of this false doctrine should come to pass. Can it be thought that God himself should give any countenance to such a vile proceeding? Did ever a false prophet work a true miracle? It is only supposed here for two reasons:-- (1.) To strengthen the caution here given against hearkening to such a one. "Though it were possible that he should work a true miracle, yet you must not believe him if he tell you that you must serve other gods, for the divine law against that is certainly perpetual and unalterable." The supposition is like that in Gal. i. 8, If we, or an angel from heaven, preach any other gospel to you--which does not prove it possible that an angel should preach another gospel, but strongly expresses the certainty and perpetuity of that which we have received. So here, (2.) It is to fortify them against the danger of impostures and lying wonders (2 Thess. ii. 9): "Suppose the credentials he produces be so artfully counterfeited that you cannot discern the cheat, nor disprove them, yet, if they are intended to draw you to the service of other gods, that alone is sufficient to disprove them; no evidence can be admitted against so clear a truth as that of the unity of the Godhead, and so plain a law as that of worshipping the one only living and true God." We cannot suppose that the God of truth should set his seal of miracles to a lie, to so gross a lie as is supposed in that temptation, Let us go after other gods. But if it be asked, Why is this false prophet permitted to counterfeit this broad seal? It is answered here (v. 3): "The Lord your God proveth you. He suffers you to be set upon by such a temptation to try your constancy, that both those that are perfect and those that are false and corrupt may be made manifest. It is to prove you; therefore see that you acquit yourselves well in the trial, and stand your ground."
II. Here is a very necessary charge given in this case,
1. Not to yield to the temptation: "Thou shalt not hearken to the worlds of that prophet, v. 3. Not only thou shalt not do the thing he tempts thee to, but thou shalt not so much as patiently hear the temptation, but reject it with the utmost disdain and detestation. Such a suggestion as this is not to be so much as parleyed with, but the ear must be stopped against it. Get thee behind me, Satan." Some temptations are so grossly vile that they will not bear a debate, nor may we so much as give them the hearing. What follows (v. 4), You shall walk after the Lord, may be looked upon, (1.) As prescribing a preservative from the temptation: "Keep close to your duty, and you keep out of harm's way. God never leaves us till we leave him." Or, (2.) As furnishing us with an answer to the temptation; say, "It is written, Thou shalt walk after the Lord, and cleave unto him; and therefore what have I to do with idols?"
2. Not to spare the tempter, v. 5. That prophet shall be put to death, both to punish him for the attempt he has made (the seducer must die, though none were seduced by him--a design upon the crown is treason) and to prevent his doing further mischief. This is called putting away the evil. There is no way of removing the guilt but by removing the guilty; if such a criminal be not punished, those that should punish him make themselves responsible. And thus the mischief must be put away; the infection must be kept from spreading by cutting off the gangrened limb, and putting away the mischief-makers. such Dangerous diseases as these must be taken in time.