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.

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.