Here is, I. A law for preserving the honour of God's worship, by providing that no creature that had any blemish should be offered in sacrifice to him, Deu 17:1. This caveat we have often met with: Thou shalt not sacrifice that which has any blemish, which renders it unsightly, or any evil matter or thing (as the following word night better be rendered), any sickness or weakness, though not discernible at first view; it is an abomination to God. God is the best of beings, and therefore whatsoever he is served with ought to be the best in its kind. And the Old Testament sacrifices in a special manner must be so, because they were types of Christ, who is a Lamb without blemish or spot (Pe1 1:19), perfectly pure from all sin and all appearance of it. In the latter times of the Jewish church, when by the captivity in Babylon they were cured of idolatry, yet they were charged with profaneness in the breach of this law, with offering the blind, and the lame, and the sick for sacrifice, Mal 1:8.
II. A law for the punishing of those that worshipped false gods. It was made a capital crime to seduce others to idolatry (ch. 13), here it is made no less to be seduced. If the blind thus mislead the blind, both must fall into the ditch. Thus God would possess them with a dread of that sin, which they must conclude exceedingly sinful when so many sanguinary laws were made against it, and would deter those from it that would not otherwise be persuaded against it; and yet the law, which works death, proved ineffectual. See here,
1. What the crime was against which this law was levelled, serving or worshipping other gods, Deu 17:3. That which was the most ancient and plausible idolatry is specified, worshipping the sun, moon, and stars; and, if that was so detestable a thing, much more was it so to worship stocks and stones, or the representations of mean and contemptible animals. Of this it is said, (1.) That it is what God had not commanded. He had again and again forbidden it; but it is thus expressed to intimate that, if there had been no more against it, this had been enough (for in the worship of God his institution and appointment must be our rule and warrant), and that God never commanded his worshippers to debase themselves so far as to do homage to their fellow-creatures: had God commanded them to do it, they might justly have complained of it as a reproach and disparagement to them; yet, when he has forbidden it, they will, from a spirit of contradiction, put this indignity upon themselves. (2.) That it is wickedness in the sight of God, Deu 17:2. Be it ever so industriously concealed, he sees it, and, be it ever so ingeniously palliated, he hates it: it is a sin in itself exceedingly heinous, and the highest affront that can be offered to Almighty God. (3.) That it is a transgression of the covenant. It was on this condition that God took them to be his peculiar people, that they should serve and worship him only as their God, so that if they gave to any other the honour which was due to him alone that covenant was void, and all the benefit of it forfeited. Other sins were transgressions of the command, but this was a transgression of the covenant. It was spiritual adultery, which breaks them marriage bond. (4.) That it is abomination in Israel, Deu 17:4. Idolatry was bad enough in any, but it was particularly abominable in Israel, a people so blessed with peculiar discoveries of the will and favour of the only true and living God.
2. How it must be tried. Upon information given of it, or any ground of suspicion that any person whatsoever, man or woman, had served other gods, (1.) Enquiry must be made, Deu 17:4. Though it appears not certain at first, it may afterwards upon search appear so; and, if it can possibly be discovered, it must not be unpunished; if not, yet the very enquiry concerning it would possess the country with a dread of it. (2.) Evidence must be given in, Deu 17:6. How heinous and dangerous soever the crime is, yet they must not punish any for it, unless there were good proof against them, by two witnesses at least. They must not, under pretence of honouring God, wrong an innocent man. This law, which requires two witnesses in case of life, we had before, Num 35:30; it is quoted, Mat 18:16.
3. What sentence must be passed and executed. So great a punishment as death, so great a death as stoning, must be inflicted on the idolater, whether man or woman, for the infirmity of the weaker sex would be no excuse, Deu 17:5. The place of execution must be the gate of the city, that the shame might be the greater to the criminal and the warning the more public to all others. The hands of the witnesses, in this as in other cases, must be first upon him, that is, they must cast the first stone at him, thereby avowing their testimony, and solemnly imprecating the guilt of his blood upon themselves if their evidence were false. This custom might be of use to deter men from false-witness bearing. The witnesses are really, and therefore it was required that they should be actually, the death of the malefactor. But they must be followed, and the execution completed, by the hands of all the people, who were thus to testify their detestation of the crime and to put the evil away from among them, as before, Deu 13:9.

Thou shalt not sacrifice unto the Lord thy God any bullock or sheep wherein is blemish,.... No sacrifice of any sort, whether burnt offering, sin offering, or peace offering, was to have any blemish in it; typical of the unblemished and immaculate Lamb of God, who, being without sin, offered himself without spot to God, and so could take away the sins of others by the sacrifice of himself; see Lev 22:18,

or any evilfavouredness; any sickness or disease upon it of any sort, which made it ill favoured to the sight, or disagreeable to the smell, or however unacceptable for sacrifice:

for that is an abomination to the Lord thy God; every such blemished and ill favoured sacrifice; see Mal 1:8.