Because God has made thee as the stars of heaven for multitude (so the preceding chapter concludes), therefore thou shalt love the Lord thy God (so this begins). Those whom God has built up into families, whose beginning was small, but whose latter end greatly increases, should use that as an argument with themselves why they should serve God. Thou shalt keep his charge, that is, the oracles of his word and ordinances of his worship, with which they were entrusted and for which they were accountable. It is a phrase often used concerning the office of the priests and Levites, for all Israel was a kingdom of priests, a holy nation. Observe the connection of these two: Thou shalt love the Lord and keep his charge, since love will work in obedience, and that only is acceptable obedience which flows from a principle of love. Jo1 5:3.
Mention is made of the great and terrible works of God which their eyes had seen, Deu 11:7. This part of his discourse Moses addresses to the seniors among the people, the elders in age; and probably the elders in office were so, and were now his immediate auditors: there were some among them that could remember their deliverance out of Egypt, all above fifty, and to them he speaks this, not to the children, who knew it by hearsay only, Deu 11:2. Note, God's mercies to us when we were young we should remember and retain the impressions of when we are old; what our eyes have seen, especially in our early days, has affected us, and should be improved by us long after. They had seen what terrible judgments God had executed upon the enemies of Israel's peace, 1. Upon Pharaoh and the Egyptians that enslaved them. What a fine country was ruined and laid waste by one plague after another, to force Israel's enlargement! Deu 11:3. What a fine army was entirely drowned in the Red Sea, to prevent Israel's being re-enslaved! Deu 11:4. Thus did he give Egypt for their ransom, Isa 43:3. Rather shall that famous kingdom be destroyed than that Israel shall not be delivered. 2. Upon Dathan and Abiram that embroiled them. Remember what he did in the wilderness (Deu 11:5), by how many necessary chastisements (as they are called, Deu 11:2) they were kept from ruining themselves, particularly when those daring Reubenites defied the authority of Moses and headed a dangerous rebellion against God himself, which threatened the ruin of a whole nation, and might have ended in that if the divine power had not immediately crushed the rebellion by burying the rebels alive, them and all that was in their possession, Deu 11:6. What was done against them, though misinterpreted by the disaffected party (Num 16:41), was really done in mercy to Israel. To be saved from the mischiefs of insurrections at home is as great a kindness to a people, and therefore lays them under as strong obligations, as protection from the invasion of enemies abroad.

Therefore thou shalt love the Lord thy God,.... Because he is so great and glorious in himself, and because he had done such great and good things for them, the Israelites, particularly in the multiplication of them, the last thing mentioned:

and keep his charge; whatsoever the Lord had charged them to observe, even what follow:

and his statutes and his judgments, and his commandments, alway; all his laws, ceremonial, judicial, and moral; and that constantly and continually, all the days of their lives.