Albert Barnes
Provision is here made for the anticipated enlargement of the borders of Israel to the utmost limits promised by God, from the river of Egypt to the Euphrates (Genesis 15:18, note; Exodus 23:31, note). This promise, owing to the sins of the people, did not receive its fulfillment until after David had conquered the Philistines, Syrians, etc.; and this but a transient one, for many of the conquered peoples regained independence on the dissolution of Solomon’s empire.
As a man’s life is to be held sacred, so are his means of livelihood; and in this connection a prohibition is inserted against removing a neighbor’s landmark: compare the marginal references.
Testify against him that which is wrong - Margin, more literally, “a falling away.” The word is used Deuteronomy 13:5 to signify apostasy or revolt; here it is no doubt to be understood in the wider sense of any departure from the Law.
Both the men, between whom the controversy is - Not the accused and the false witness, but the plaintiff and defendant (compare Exodus 23:1) who were summoned before the supreme court held, as provided in Deuteronomy 17:0, at the sanctuary. The judges acted as God’s representative; to lie to them was to lie to Him.
See the marginal references.