Four others, it is true, contain the word God, and three of them the word Lord, also.

But who is this Lord God of whom they speak?
Without the fourth commandment it is impossible to tell; for idolaters of every grade apply these terms to the multitudinous objects of their adoration.

With the fourth commandment to point out the Author of the decalogue, the claims of every false god are annulled at one stroke; for the God who here demands our worship is not any created being, but the One who created them all.
The maker of the earth and sea, the sun and moon, and all the starry host, the upholder and governor of the universe, is the One who claims, and who, from his position, has a right to claim, our supreme regard in preference to every other object.

The commandment which makes known these facts is therefore the very one we might suppose that power would undertake to change, which designed to exalt itself above God.

God gave the Sabbath as a memorial of himself, a weekly reminder to the sons of men, of his work in creating the heavens and the earth, a great barrier against atheism and idolatry.