Verse 14. - In obedience to the commands which he had received (ver. 10), Moses returned to the camp at the foot of Sinai, and issued the order that the people were to purify themselves and wash their garments during that day and the next, and be ready for a great solemnity on the third day. He must also, at the same time, have given directions for the construction of the fence, which was to hedge in the people (ver. 12), and which he speaks of as constructed in ver. 23.

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.And Moses went down from the mount unto the people,.... The same day that he went up, the fourth day of the month:

and sanctified the people; instructed them and ordered them what they should do for their sanctification, in order to their hearing the law from the mouth of the Lord:

and they washed their clothes; as the Lord had directed Moses to enjoin them, and as he had commanded them; see Gill on Exodus 19:10.