Deuteronomy 20

The law begins at the exact instant fear takes hold - the moment you crest the hill and see the horses, and chariots, and a people more than thou (v. 1). Every item on that list is a genuine disadvantage. The war-chariot was the heaviest weapon the ancient world had, the thing a man on foot could barely answer; cavalry outran and outflanked infantry; sheer numbers simply swallowed you. Israel, marching in mostly without such things, would feel every bit of the gap.

The command does not deny the danger or scold the soldier for feeling it. It sets one larger fact against the whole of it: God is with you, the God which brought thee up out of the land of Egypt. That last phrase is no throwaway. The previous time Israel faced massed horses and chariots, they stood trapped at the sea and watched those chariots sink. The God who broke Pharaoh's armor is the same God going out with them now.

The remedy for fear is a longer memory.

Notice who steps forward to address the troops on the eve of battle: the priest shall approach and speak unto the people (v. 2). A priest, not a general or a king. And his charge is striking for what it leaves out. He says nothing about the enemy's weakness or Israel's strength, nothing tactical at all. He piles up four ways of saying one thing - let not your hearts faint, fear not, and do not tremble, neither be ye terrified because of them (v. 3) - and then names the single ground for all of it: the LORD your God is he that goeth with you, to fight for you against your enemies, to save you (v. 4).

That is the entire theology of Israel's warfare in one sentence. The battle is the LORD's; the people's part is to trust and not to faint. Fear wants to flood the heart and make the odds look final. The priest stands in front of the army and, before a sword is drawn, names the One who is already there. Courage in Scripture is fear answered by a greater certainty.

Then the officers do something no other ancient army would dream of: they begin sending soldiers home. Three exemptions come first, and each one protects an unfinished good thing in a man's life. The man who has built a new house, and hath not dedicated it (v. 5) - who has not yet moved in and begun life under that roof - is sent back, lest he die and another man dedicate it. The man who has planted a vineyard, and hath not yet eaten of it (v. 6) is sent home; a vineyard takes years to bear, and the one who waited for it should be the one to taste it.

And the man who has betrothed a wife, and hath not taken her (v. 7) is released to go and marry; the covenant of marriage is too good a thing to be cut off before it has even begun. The logic is the same each time: the home, the harvest, the marriage are not expendable to the war machine. War may sometimes be necessary, but the ordinary goods of a human life - shelter, fruit, love - are sacred, and God will not let them be swallowed up cheaply.

An army built on these rules could never be a juggernaut. It could only ever win the way Israel was meant to win - by the hand of God.

The fourth exemption is the most surprising of all, because it lets a man leave for no reason but his own heart: What man is there that is fearful and fainthearted? let him go and return unto his house (v. 8). No army of conquest releases its frightened men; fear is exactly what officers are usually trained to override. But here the soldier whose courage has failed is sent home without shame, and the stated reason is mercy toward the others: lest his brethren's heart faint as well as his heart. Fear is contagious.

One trembling man in the ranks can hollow out the resolve of the men beside him, and God will not have the army eaten away from within. There is something tender in this too. The fearful man is not punished; he is simply not made to carry what he cannot. Only after these four words have thinned the ranks are leaders appointed: they shall make captains of the armies to lead the people (v. 9).

The order matters. First the heart of the army is set right - freed of distraction, freed of dread - and only then is it organized for battle. What is left is small, willing, and unafraid, the kind of force that can only be explained by the One who fights for it.

Before a single siege-ramp is raised, the law fixes the first move - and the word order is deliberate. The soldiers may be drawn up to fight, the city may be fully in their power to assault, and still the opening act commanded of them is to proclaim peace unto it (v. 10). The attack is not the first thing; the offer is. Judgment is never God's opening word. And the offer is real: if it make thee answer of peace, and open unto thee, the city is not destroyed at all; its people shall be tributaries… and they shall serve thee (v. 11).

They live. They keep their homes. The whole calamity of war is averted the moment the city is willing to receive peace. Only if a city will make no peace… but will make war (v. 12) does the siege follow. The point worth sitting with is the order itself: peace held out first, freely, to a city that has done nothing yet to deserve mercy. That is the shape of how God deals with the world - the offer goes out before the sword is ever drawn, and many who could be destroyed are spared simply because they did not refuse it.

For the city that chooses war, verses 13 and 14 describe what follows, and the text does not soften it: when the LORD delivers the city, the fighting men - every male thereof - are struck, while the women, and the little ones, and the cattle, and all… the spoil are preserved (vv. 13-14). These are sober verses, and they belong to a world whose warfare was brutal in ways modern readers rightly recoil from. But two things in the text deserve notice rather than a rush past them.

First, this is the harshest outcome only for a city that has been offered peace and refused it, choosing war (v. 12); the destruction comes as a last resort, after mercy was already offered. Second, even here a real limit is drawn: the non-combatants are spared, and the city's wealth becomes provision. By the standards of the ancient world, where the total annihilation of a defeated city was common boasting, this is a code that already pulls war back from its worst impulses.

It is a war hedged about with offered mercy at the front and preserved life at the end, even while war remains war.

Verse 15 quietly marks off exactly how far this law of offered peace reaches: Thus shalt thou do unto all the cities which are very far off from thee, which are not of the cities of these nations. This whole protocol - proclaim peace first, spare the city that submits, preserve the women and children even of a city that fights - governs the distant cities, the ones outside the borders of the land Israel was given.

It is the general rule for Israel's dealings with the nations around them, and its default posture is the offer of peace. This matters enormously for reading what comes next. The far more severe command of verses 16-18 is a deliberate, bounded exception, marked off here by this very verse, with no claim to be the general pattern for Israel's dealings with the nations. The reader is being told, in advance, that the ordinary law of war for Israel begins with peace, and that the cities within the land stand under a special and limited judgment for reasons the text is about to give.

Verse 15 is the hinge that keeps the two from being confused.

Here the law turns to its hardest ground, and honesty requires that we let the text speak plainly. The cities of these people - the nations already living in the land given to Israel for an inheritance - stand under a far more severe command than the distant cities of verses 10-15: thou shalt save alive nothing that breatheth (v. 16). This is the measure sometimes called the “devotion to destruction.” It is grievous, and Scripture does not present it as a casual or ordinary thing.

What the text does do is frame it carefully, in three ways the reader should hold together. First, it is bounded: it names six specific nations (v. 17) in one specific land at one specific moment, not war in general. Second, it is set against the immediately preceding law, where Israel's ordinary dealing with cities was to proclaim peace first (v. 10) - a marked and bounded exception to that general posture. Third, and most importantly, the very next verse states its reason, and the reason is preservation, not plunder, pride, or hatred of a people.

The whole weight of the command rests on the purpose given in verse 18, and the text wants that purpose read before any conclusion is drawn.

Verse 18 gives the entire rationale, and it is worth weighing slowly: That they teach you not to do after all their abominations, which they have done unto their gods; so should ye sin against the LORD your God. The danger is named exactly - not the existence of these nations as such, but the pull of their religious practices, the abominations… done unto their gods. Scripture elsewhere is explicit about what those practices included: child sacrifice, ritual prostitution, divination, and the burning of sons and daughters in the fire (Lev. 18:21-25; Deut. 12:31).

And the command did not fall out of nowhere. Generations earlier, God had told Abraham his descendants would not yet take the land, for the iniquity of the Amorites is not yet full (Gen. 15:16) - a stunning line that shows God waiting four centuries, withholding judgment until the wickedness had run its full and unmistakable course. The land itself is said to vomit out its inhabitants for what they did (Lev. 18:25). So this is portrayed as a long-delayed judgment on a specific and extreme corruption, executed once, with the stated aim of keeping that corruption from devouring Israel too.

The point of the command is not Israel's greatness but Israel's preservation - that the people meant to bless all nations not be hollowed out by the very evils they were sent to displace. Crucially, the text never holds this out as a model for any later war or as a principle to be carried forward; it ties it tightly to that one hour, that one land, and that one purpose, and there it leaves it.

And then, in the middle of the chapter's most severe passage, comes one of the most unexpected mercies in the law: even in a long siege, the fruit trees are to be spared. When thou shalt besiege a city a long time… thou shalt not destroy the trees thereof by forcing an axe against them: for thou mayest eat of them, and thou shalt not cut them down (v. 19). The standard tactic of ancient siege warfare was to strip the countryside bare - to fell every tree for ramps and engines and firewood, and to ruin the land so the enemy could never recover.

Here God forbids it, and the reason He gives is extraordinary: for the tree of the field is man's life. The fruit tree feeds people; it took years to grow; it will feed people again long after the siege is over. It is not to be sacrificed to the appetite of war. Only trees that bear no food may be used for the siege-works (v. 20). The restraint is the thing to notice.

Even in the chapter that contains the hardest command in the book, God draws a line that war is not allowed to cross. His judgments, even at their most severe, are never wanton; He remembers the orchard and the generations who will eat from it. A God who will not let an army waste a fruit tree is a God whose severity is always bounded by mercy.