Biblical Commentary on the Old Testament, by Carl Friedrich Keil and Franz Delitzsh, [1857-78], at sacred-texts.com
Instructions for Future Wars - Deuteronomy 20
The instructions in this chapter have reference to the wars which Israel might wage in future against non-Canaanitish nations (Deu 20:15.), and enjoin it as a duty upon the people of God to spare as much as possible the lives of their own soldiers and also of their enemies. All wars against their enemies, even though they were superior to them in resources, were to be entered upon by them without fear in reliance upon the might of their God; and they were therefore to exempt from military service not only those who had just entered into new social relations, and had not enjoyed the pleasures of them, but also the timid and fainthearted (Deu 20:1-9). Moreover, whenever they besieged hostile towns, they were to offer peace to their enemies, excepting only the Canaanites; and even if it were not accepted, they were to let the defenceless (viz., women and children) live, and not to destroy the fruit-trees before the fortifications (Deu 20:10-20).
Instructions Relating to Military Service. - If the Israelites went out to battle against their foes, and saw horses and chariots, a people more numerous than they were, they were not to be afraid, because Jehovah their God was with them. Horses and chariots constituted the principal strength of the enemies round about Israel; not of the Egyptians only (Exo 14:7), and of the Canaanites and Philistines (Jos 17:16; Jdg 4:3; Sa1 13:5), but of the Syrians also (Sa2 8:4; Ch1 18:4; Ch1 19:18; cf. Psa 20:8).
If they were thus drawing near to war, i.e., arranging themselves for war for the purpose of being mustered and marching in order into the battle (not just as the battle was commencing), the priest was to address the warriors, and infuse courage into them by pointing to the help of the Lord. "The priest" is not the high priest, but the priest who accompanied the army, like Phinehas in the war against the Midianites (Num 31:6; cf. Sa1 4:4, Sa1 4:11; Ch2 13:12), whom the Rabbins call המלחמה משׁיח (the anointed of the battle), and raise to the highest dignity next to the high priest, no doubt simply upon the ground of Num 31:6 (see Lundius, jd. Heiligth. p. 523).
Moreover, the shoterim, whose duty it was, as the keepers of the genealogical tables, to appoint the men who were bound to serve, were to release such of the men who had been summoned to the war as had entered into domestic relations, which would make it a harder thing for them to be exposed to death than for any of the others: for example, any man who had built a new house and had not yet consecrated it, or had planted a vineyard and not yet eaten any of the fruit of it, or was betrothed to a wife and had not yet married her, - that such persons might not die before they had enjoyed the fruits of what they had done. "Who is the man, who," i.e., whoever, every man who. "Consecrated the house," viz., by taking possession and dwelling in it; entrance into the house was probably connected with a hospitable entertainment. According to Josephus (Ant. iv. 8, 41), the enjoyment of them was to last a year (according to the analogy of Deu 24:5). The Rabbins elaborated special ceremonies, among which Jonathan in his Targum describes the fastening of slips with sentences out of the law written upon them to the door-posts, as being the most important (see at Deu 6:9 : for further details, see Selden, de Synedriis l. iii. c. 14, 15). Cerem is hardly to be restricted to vineyards, but applied to olive-plantations as well (see at Lev 19:10). חלּל, to make common, is to be explained from the fact, that when fruit-trees were planted (Lev 19:23.), or vines set (Jdg 19:24), the fruit was not to be eaten for the first three years, and that of the fourth year was to be consecrated to the Lord; and it was only the fruit that was gathered in the fifth year which could be applied by the owner to his own use, - in other words, could be made common. The command to send away from the army to his own home a man who was betrothed but had not yet taken his wife, is extended still further in Deu 24:5, where it is stated that a newly married man was to be exempt for a whole year from military service and other public burdens. The intention of these instructions was neither to send away all persons who were unwilling to go into the war, and thus avoid the danger of their interfering with the readiness and courage of the rest of the army in prospect of the battle, nor to spare the lives of those persons to whom life was especially dear; but rather to avoid depriving any member of the covenant nation of his enjoyment of the good things of this life bestowed upon him by the Lord.
The first intention only existed in the case of the timid (the soft-hearted or despondent). ימּס ולא, that the heart of thy brethren "may not flow away," i.e., may not become despondent (as in Gen 17:15, etc.).
When this was finished, the shoterim were to appoint captains at the head of the people (of war). פּקד, to inspect, to muster, then to give the oversight, to set a person over anything (Num 3:10; Num 4:27). The meaning "to lead the command" (Schultz) cannot be sustained; and if "captains of the armies" were the subject, and reference were made to the commanders in the war, the article would not be omitted. If the shoterim had to raise men for the war and organize the army, the division of the men into hosts (Zebaoth) and the appointment of the leaders would also form part of the duties of their office.
Instructions Concerning Sieges. - Deu 20:10, Deu 20:11. On advancing against a town to attack it, they were "to call to it for peace," i.e., to summon it to make a peaceable surrender and submission (cf. Jdg 21:13). "If it answered peace," i.e., returned an answer conducing to peace, and "opened" (sc., its gates), the whole of its inhabitants were to become tributary to Israel, and serve it; consequently even those who were armed were not to be put to death, for Israel was not to shed blood unnecessarily. מס does not mean feudal service, but a feudal slave (see at Exo 1:11).
If the hostile town, however, did not make peace, but prepared for war, the Israelites were to besiege it; and if Jehovah gave it into their hands, they were to slay all the men in it without reserve ("with the edge of the sword," see at Gen 34:26); but the women and children and all that was in the city, all its spoil, they were to take as prey for themselves, and to consume (eat) the spoil, i.e., to make use of it for their own maintenance.
It was in this way that Israel was to act with towns that were far off; but not with the towns of the Canaanites ("these nations"), which Jehovah gave them for an inheritance. In these no soul was to be left alive; but these nations were to be laid under the ban, i.e., altogether exterminated, that they might not teach the Israelites their abominations and sins (cf. Deu 7:1-4; Deu 12:31). כּל־נשׁמה, lit., every breath, i.e., everything living, by which, however, human beings alone are to be understood (comp. Jos 10:40; Jos 11:11, with Deu 11:14).
When they besieged a town a long time to conquer it, they were not to destroy its trees, to swing the axe upon them. That we are to understand by עצהּ the fruit-trees in the environs and gardens of the town, is evident from the motive appended: "for of them (ממּנּוּ refers to עץ as a collective) thou eatest, and thou shalt not hew them down." The meaning is: thou mayest suppress and destroy the men, but not the trees which supply thee with food. "For is the tree of the field a man, that it should come into siege before thee?" This is evidently the only suitable interpretation of the difficult words השּׂדה עץ האדם כּי, and the one which has been expressed by all the older commentators, though in different ways. But it is one which can only be sustained grammatically by adopting the view propounded by Clericus and others: viz., by pointing the noun האדם with ה interrog., instead of האדם, and taking אדם as the object, which its position in the sentence fully warrants (cf. Ewald, 324, b. and 306, b.). The Masoretic punctuation is founded upon the explanation given by Aben Ezra, "Man is a tree of the field, i.e., lives upon and is fed by the fruits of the trees," which Schultz expresses in this way, "Man is bound up with the tree of the field, i.e., has his life in, or from, the tree of the field," - an explanation, however, which cannot be defended by appealing to Deu 24:6; Ecc 12:13; Eze 12:10, as these three passages are of a different kind. In no way whatever can האדם be taken as the subject of the sentence, as this would not give any rational meaning. And if it were rendered as the object, in such sense as this, The tree of the field is a thing or affair of man, it would hardly have the article.
"Only the trees which thou knowest that they are not trees of eating (i.e., do not bear edible fruits), mayest thou hew down, and build a rampart against the town till it come down," i.e., fall down from its eminence. For ירד as applied to the falling or sinking of lofty fortifications, see Deu 28:52; Isa 32:19. מצור, compressing or forcing down; hence, as applied to towns, במּצור בּוא, to come into siege, i.e., to be besieged (Deu 20:19; Kg2 24:10; Kg2 25:2). In Deu 20:20 it is used to denote the object, viz., the means of hemming in a town, i.e., the besieging rampart (cf. Eze 4:2).