Set bounds unto the people - The low line of alluvial mounds at the foot of the cliff of Ras Safsafeh exactly answers to the bounds which were to keep the people off from touching the mount: but the bounds here spoken of were to be set up by Moses.

Thou shalt set bounds - Whether this was a line marked out on the ground, beyond which they were not to go, or whether a fence was actually made to keep them off, we cannot tell; or whether this fence was made all round the mountain, or only at that part to which one wing of the camp extended, is not evident.

This verse strictly forbids the people from coming near and touching Mount Sinai, which was burning with Fire. The words therefore in Exodus 19:15, אל תגשו אל אשה al tiggeshu el ishshah, come not at your wives, seem rather to mean, come not near unto the Fire; especially as the other phrase is not at all probable: but the fire is, on this occasion, spoken of so emphatically (see Deuteronomy 5:4, Deuteronomy 5:5, Deuteronomy 5:22-25) that we are naturally led to consider אשה ishshah here as האש ha-esh transposed, or to say, with Simon in his Lexicon, אשה faem, idem quod masc. אש ignis. So among other instances, we have אבר and אברה a wing; אור and אורה light; אמץ and אמצה strength; and אמר and אמרה a speech - Burt. See Kennicott's Remarks.

Whosoever toucheth the mount shall be surely put to death - The place was awfully sacred, because the dreadful majesty of God was displayed on it. And this taught them that God is a consuming fire, and that it is a fearful thing to fall into the hands of the living God.

And thou shall set bounds to the people round about,.... That is, round about the mountain, by drawing a line, throwing up a foss or ditch, or else by laying up heaps of stones or sand, which might be come at easily, or bushes and branches of trees, which grew thick on the mount, from whence it had its name; but be it what will that were used, these were to signify, that so far the people might go, but no further, which their curiosity might prompt them to:

saying, take heed unto yourselves that ye go not up into the mount; so far were they from being allowed to go up to the top of it, that they were not allowed to ascend it at all, or to go any further than where the ascent or rise began; it was at their peril to ascend, and this was what they were to take heed unto, lest they incurred danger:

or touch the border of it; it being the mountain of God, and relatively holy through his presence on it:

whosoever toucheth the mount shall be surely put to death; which severe law was made to deter them from any attempt to go up the mountain, since it was death even to touch it, see Hebrews 12:18.

And thou shalt set bounds unto the people round about, saying, Take heed to yourselves, that ye go not up into the mount, or touch the border of it: whosoever toucheth the mount shall be surely put to death:

19:12 Set bounds - Probably he drew a ditch round at the foot of the hill, which none were to pass upon pain of death. This was to intimate, 1st, That awful reverence which ought to possess the minds of all that worship God. 2dly, The distance which worshippers were kept at under that dispensation, which we ought to take notice of, that we may the more value our privilege under the gospel, having boldness to enter into the holiest by the blood of Jesus, Heb 10:19.

19:9-15 The solemn manner in which the law was delivered, was to impress the people with a right sense of the Divine majesty. Also to convince them of their own guilt, and to show that they could not stand in judgment before God by their own obedience. In the law, the sinner discovers what he ought to be, what he is, and what he wants. There he learns the nature, necessity, and glory of redemption, and of being made holy. Having been taught to flee to Christ, and to love him, the law is the rule of his obedience and faith.