In this chapter Moses selects another occasion for transgressing the First Commandment, an occasion called spiritual pride because it boasts of its righteousness and merits. This is trust in one’s own works, and no plague and opponent of faith or trust in the mercy of God is more destructive. Therefore Moses demolishes it here with many words throughout the whole chapter. It robs God of His glory, for these two cannot stand side by side: to glory in God and His mercy, and to glory in ourselves because of our righteousness and works. He disproves this righteousness with three strong arguments.

Martin Luther on Deuteronomy chapter 9: LW Vol.9, Pg.102-105

1. Those Gentiles deserved to be expelled on account of their godlessness.

He says this: “For not because of your righteousnesses or the uprightness of your heart will you go in; but because they dealt godlessly, the Lord cast them out” (v. 5). With these words we, too, should be instructed if we see others smitten either by ourselves or by others. It does not follow that since you or others smite that man, therefore you or others are more righteous than he. Otherwise the tower of Siloam, which fell on many in Jerusalem (Luke 13:4), would also be regarded as just. But it is God who smites the godless, as he says here. Whether He does these things through a tower, fire, water, beasts, your hand or another’s, makes no difference. Nothing else takes place there than that the just God has smitten the godless.

Furthermore, you should fear this example. The godless one is smitten that you may be terrified, just as Christ explains in Luke 13:5, saying: “You shall all perish this way.” And Paul says in Rom. 11:21–22, as he forbids the Gentiles by means of the same argument to be proud over the ruin of the Jews: “See to it that He spares you; otherwise you, too, shall be cut off”; and Rom. 2:3: “Man, when you judge those who do such things, and you do the same, do you think that you shall escape the judgment of God?”

Outstanding is also the statement of St. Gregory: “When we see anyone sin, we should first weep over ourselves in their calamity, because we have either fallen like them or we can fall.”² 

Someone has summed this up in the following lowing verse: “We either are, have been, or can be what this man is.”³ 

A person recorded in The Lives of the Fathers said, when he had heard of the lapse of a brother: “He yesterday, I today.”⁴ 

Hence when someone else is smitten, this should be our thought: “It is your business when the neighboring wall is on fire.”⁵ Yes, with a feeling of pity and sympathy the godless are to be destroyed or struck down by us as we remember that we are the instrument of God and are ourselves perhaps to be cast as a whip into the fire after we have blasted the evildoers.

2. The second argument is the authority of the divine promise.

The Lord cast them out “that He might fulfill His oath and Word which He promised to your fathers” (v. 5). Nothing stronger could have been said against trust in one’s own righteousness. For where were the sons of Israel when God promised the land of Canaan to their father Abraham, who up to that time was sterile and hopelessly childless? If they receive and occupy the land through the promise of God, therefore, it is not because of merits or their own righteousness but from the simple grace and goodness of God, which He poured out over the unworthy and those not yet born.

Why does He promise? Perhaps because those who would come after 430 years would deserve it? Far from it! He who promised out of goodness alone also fulfilled His Word out of mercy alone.

Paul uses this argument in his letters to the Galatians (3:2 ff.) and the Romans (4:1 ff.), when he proves most powerfully that righteousness has to come about by the mercy of God once promised, not by works.

3. The third argument is experience itself.

He says: “Since you are a stiff-necked people, etc.” (v. 6). By such a neck they had not deserved even to come close to the land; for God was so incensed that He would have rather destroyed them than the Gentiles in the desert. Just as the psalm says (106:26): “And He stretched out His hand that He might cast them down in the desert” and would have turned His promise elsewhere, namely, toward the descendants of Moses (Num. 14:12). Finally He laid them all low in the desert to the last man, except Joshua and Caleb, so that neither Moses nor Aaron entered the land. Hence that they should enter the land by their merit was so far from being the case that the very opposite should much rather have happened to them—as it also turned out—if they were to be dealt with according to merit. Paul also uses this argument in Rom. 4:14 ff., where he says: “If the inheritance is by the Law, faith is void, the promise is abolished; for the Law works wrath.” So you see that both Moses and Paul use the same dialectic of the spirit against the righteousness of works and on behalf of the grace and mercy of God.

The conclussion thus is: Evil is well deserved, whereas good is but due to God´s goodness and his most gracious promises long ago:

Therefore all these things are also written for our learning (Rom. 15:4), that we may learn that if any evil comes upon the godless, it comes indeed by their merit. As for the rest, if it does not break in upon us but we enjoy good things, this is due not to our righteousness but to divine goodness, by which such things have been provided and promised for us from eternity; for we deserved the very opposite. Hence the verdict stands: Not on account of our righteousness is any good thing given to us, but in order that God may fulfill the Word which He willed from eternity, lest we be puffed up and make an idol out of our righteousness. We are to know that we have one God, from whom we freely receive all things, through His sheer goodness poured out over the unworthy. So also the patriarch Jacob confesses (Gen. 32:10): “I am too small for all Thy mercies,” that is, not only for a mercy which may be large but for any at all, however small and slight it may be.

For remember, who You are and where You come from – even though through God´s grace and goodness, You have now been saved and brought to a new life in IX:

Then Moses administers a healing antidote to this pestilence, for this monster of one’s own righteousness is so formidable that it cannot be sufficiently restrained. He sets before their eyes all the former misdeeds of the people and commands them to remember such things; and forcibly, before all, with great power of words, he recalls their sin at Mt. Sinai, when they worshiped the calf. What can heal the sickness of this pride more promptly than to remember former godlessness and crimes?

What does this people have except what makes it ashamed to lift its eyes to heaven? Just as Paul says to the Ephesians: “Of which you are now ashamed.”⁶ Hence He also permitted David, Moses, Peter, Paul, and other great men to fall, that they might be humbled, become ashamed before God, and rely on His goodness alone. Therefore Peter (2 Peter 1:9) sharply lashes out at those who forget the forgiveness of former sins, become smug and cold, and then stiff-necked and proud.

So, in the end, what reason do we have to boast? None! Therefore, we can but laud and praise God´s grace and goodness, who is willing to forgive and grant life even to those deserving death:

Finally he closes: “You have been rebellious against the Lord from the day that I knew you” (v. 24). What a worthy commendation, what merits, what righteousness of a holy people, namely, disobedience to the divine voice! Go on now and boast, brag, be puffed up, saying that the land has been given to you because of your righteousnesses, you who do not deserve to hear anything but that you are a stiff-necked people and always disobedient to the Lord! Indeed, do such merits deserve such royal wealth and not rather a thousand deaths and crosses? What more dreadful a thing can be said than to be disobedient to the Lord? Nevertheless, that celebrated and blessed land is given to this disobedience. What does Israel have left here to be proud of? Should it not rather put its face into the dust and say: “I am worse than all the Gentiles, and great and undeserved is Thy grace, that I receive that land”? Furthermore, if that holy and special Israel is such a people before God, what are we Gentiles and sinners?

In the end it is but God´s most Holy Name, Honor and Glory that He pardons sinners and saves those lost:

See in how many words Moses here accuses the people in this very prayer which he prays for them as he says: “Do not regard the stubbornness of this people, or their wickedness, or their sin, lest the land from which Thou didst bring us say, etc.” (vv. 27–28). Nothing is told here about the people except things for which they deserved death. The one salvation was this, that their destruction would endanger the name of God. Hence, that the name of God might not be blasphemed, pardon not otherwise to be given is conferred on them. They would have been destined for total destruction if the glory of the name of God, which was called out over them (Jer. 15:16), could have been saved. From this place many others, especially David in the Psalter, took this safe and dependable argument (Ps. 25:11): “On account of Thy name, Lord, have pity on my sin, etc.”; and Joshua (7:9): “What wilt Thou do by Thy great name,” by which we are called?