Matthew Henry on Exodus 19:16–end
Now, at length, comes that memorable day, that terrible day of the Lord, that day of judgment, in which Israel heard the voice of the Lord God speaking to them out of the midst of the fire, and lived, Deu 4:33. Never was there such a sermon preached, before nor since, as this which was here preached to the church in the wilderness. For,
I. The preacher was God himself (Exo 19:18): The Lord descended in fire, and (Exo 19:20), The Lord came down upon mount Sinai. The shechinah, or glory of the Lord, appeared in the sight of all the people; he shone forth from mount Paran with ten thousands of his saints (Deu 33:2), that is, attended, as the divine Majesty always is, by a multitude of the holy…
Read the whole note in the consoleJamieson-Fausset-Brown on Exodus 19:21
the Lord said unto Moses, Go down, charge the people--No sooner had Moses proceeded a little up the mount, than he was suddenly ordered to return, in order to keep the people from breaking through to gaze--a course adopted to heighten the impressive solemnity of the scene. The strict injunctions renewed to all, whatever their condition, at a time and in circumstances when the whole multitude of Israel were standing at the base of the mount, was calculated in the highest degree to solemnize and awe every heart.
Next: Exodus Chapter 20
Adam Clarke on Exodus 19:23
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.
John Gill on Exodus 19:23
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…