Here is the repetition of the Ten Commandments, in which observe (1) though they had been spoken before, and written, yet they are, again, rehearsed, for precept must be upon precept, and line upon line, and all little enough to keep the Word of God in our minds and to preserve and renew the impressions of it. We have need to have the same things often inculcated upon us (see Philippians 3.1). (2) There is some variation here from that record (Exodus 20) as there is between the Lord’s Prayer as it is in Matthew 6 and as it is in Luke 11. In both, it is more necessary that we tie ourselves to the things than to the words unalterably. (3) The most considerable variation is in the Fourth Commandment. In Exodus 20, the reason annexed is taken from the creation of the world. Here, it is taken from their deliverance out of Egypt because that was typical of our redemption by Jesus Christ, in remembrance of which the Christian Sabbath was to be observed: Remember that thou wast a servant, and God brought thee out (verse 15). – Matthew Henry (1662-1714), commenting on Deuteronomy 5.6-22.