Bursts of swirling blue, splatters of crackling gold, and explosions of racing red fill the sky, and then, for the finale, some kid comes out and twirls a sparkler. Is that what we have with this final word from the fire? Has the fire died so that were left with only smoldering embers. No, we may have left the glories of the heavens, but now we are plunged to the depths. These ocean depths can be as mysterious as the starry heavens.
All the other commands, taken on the surface, deal with external obedience, this one goes down to the heart, and thus, acts as commentary on all the Decalogue. Listen to the testimony of M&M&M:
“The tenth commandment is where the Decalogue ends, but it is, in fact, the point at which every breach of the law begins—when by our ‘own evil desire’ we are ‘dragged away and enticed’ (Jas 1:14). —Alec Moyter
“Improper desire is the root of all evil. It can seldom be reached by human legislation, but it is open to the Searcher of hearts. The intent is that which, in the last resort, determines the moral character of the act. This last ‘word’ is, therefore, the interpreting clause of the whole Decalogue (Rom. Vii. 7).” —J.G. Murphy
“It [the tenth commandment] is presented here as the last commandment because it points to the root of all breaches of the covenant as coming from wrong inner disposition.” — John Mackay
You must read all other commands in light of this one. You don’t understand God’s law until you see it as dealing with the heart. All the law is only a sizzling fuse with no bang when read heartlessly. When Jesus says, “You have heard it said, but I say unto you (Matthew 5:21–48),” He isn’t contradicting the law, but the Pharisees heartless reading of the law. His disciples are to display a righteousness superior to that of the Pharisees (Matthew 5:20), a righteousness that is superior, that is true righteousness, because it springs forth from the heart.
God’s love kindles our love. God’s love both ignites and fuels ours. We love because He first loved us (1 John 4:19). Redemption sets the heart right (Deuteronomy 30:6). Redemption replaces a heart of stone with a heart of flesh (Ezekiel 11:19). We come to these words of law through a preface of grace, “I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery (Exodus 20:2 (ESV).” When the redeemed heart hears, “You shall not covet,” it responds, “Whom have I in heaven but you? And there is nothing on earth that I desire besides you (Psalm 73:25 ESV).” When a redeemed heart meets the law of God its like sparks of love meeting a powder keg—from the depths, glory to heaven.