(11) Against the third day.—There is no special “significance” in this mention of “the third day.” The important point is, that the purification was to continue through two entire days—one day not being sufficient. This taught the lesson that man’s defilement is, in the sight of God, very great.

The Lord will come down in the sight of all the people.—See the comment on Exodus 19:9.

Exodus 19:11. In the sight of all the people — Though they should see no manner of similitude, yet they should see so much as would convince them, that God was among them of a truth. And so high was the top of mount Sinai, that it is supposed not only the camp of Israel, but even the countries about might discern some extraordinary appearance of glory upon it.

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.Sanctify them - The injunction involves bodily purification and undoubtedly also spiritual preparation. Compare Hebrews 10:22. The washing of the clothes was an outward symbol well understood in all nations. 9-15. The Lord said unto Moses, Lo, I come … in a thick cloud, &c.—The deepest impressions are made on the mind through the medium of the senses; and so He who knew what was in man signalized His descent at the inauguration of the ancient church, by all the sensible tokens of august majesty that were fitted to produce the conviction that He is the great and terrible God. The whole multitude must have anticipated the event with feelings of intense solemnity and awe. The extraordinary preparations enjoined, the ablutions and rigid abstinence they were required to observe, the barriers erected all round the base of the mount, and the stern penalties annexed to the breach of any of the conditions, all tended to create an earnest and solemn expectation which increased as the appointed day drew near. For the third day from this time, and the fiftieth day from the passover, as was noted before,

the Lord will come down in a visible and glorious manifestation of his presence.

And be ready against the third day,.... Not the third day of the month, but the third day from hence, this being the fourth, and the morrow the fifth, and the third day, the day following that, the sixth, on which day it is generally agreed by the Jews that the law was given; see Gill on Exodus 19:16.

for the third day the Lord will come down in the sight of all the people upon Mount Sinai; which must be understood, consistent with his omnipresence, and is only expressive of some visible display of his power, and of some sensible token of his presence to the people; he was now upon it in the pillar of cloud, but then he would appear in another manner, and descend in a thick cloud and fire, which all the people would see, though they could not see the similitude of anything in it.

And be ready against the third day: for the third day the LORD will come down in the sight of all the people upon mount Sinai.