The people cannot come up - Either because they had been so solemnly forbidden that they would not dare, with the penalty of instant death before their eyes, to transgress the Divine command; or the bounds which were set about the mount were such as rendered their passing them physically impossible.

And sanctify it - וקדשהי vekiddashio. Here the word קדש kadash is taken in its proper literal sense, signifying the separating of a thing, person or place, from all profane or common uses, and devoting it to sacred purposes.

And Moses said unto the Lord,.... Upon his giving such strict orders both with respect to the people and the priests:

the people cannot come up to Mount Sinai; suggesting as if there was no need for him to go down on that account, to give them a charge not to break through and gaze; since, as he thought, there was no probability that they ever would attempt it, seeing such a solemn charge had been given, nor any possibility of it, since such a fence was made:

for thou chargedst us, saying, set bounds about the mount, and sanctify it; and accordingly bounds have been set, that the people may not go up it, and the place has been declared sacred, that so none will presume to do it, according to the solemn charge that has been given: some (a) read the preceding clause by way of interrogation, "may not the people come up to Mount Sinai?" may not any of them? or, if any of them, who may? and there was the greater reason for asking such a question, since the priests that drew near to God might not, and so the next words are conceived to be an answer to it.

(a) So some in Vatablus.

And Moses said unto the LORD, The people cannot come up to mount Sinai: for thou chargedst us, saying, Set bounds about the mount, and sanctify it.

19:16-25 Never was there such a sermon preached, before or since, as this which was preached to the church in the wilderness. It might be supposed that the terrors would have checked presumption and curiosity in the people; but the hard heart of an unawakened sinner can trifle with the most terrible threatenings and judgments. In drawing near to God, we must never forget his holiness and greatness, nor our own meanness and pollution. We cannot stand in judgment before him according to his righteous law. The convinced transgressor asks, What must I do to be saved? and he hears the voice, Believe in the Lord Jesus Christ, and thou shalt be saved. The Holy Ghost, who made the law to convince of sin, now takes of the things of Christ, and shows them to us. In the gospel we read, Christ hath redeemed us from the curse of the law, being made a curse for us. We have redemption through his blood, even the forgiveness of sins. Through him we are justified from all things, from which we could not be justified by the law of Moses. But the Divine law is binding as a rule of life. The Son of God came down from heaven, and suffered poverty, shame, agony, and death, not only to redeem us from its curse, but to bind us more closely to keep its commands.