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 עֵצָהּ the fruit-trees in the environs and gardens of the town, is evident from the motive appended: “for of them (מִמֶּנּוּ refers to עֵץ 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 הַשָּׂדֶה עֵץ הָאָדָם כִּי, 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 הֶאָדָם with ה interrog., instead of הָאָדָם, and taking אָדָם 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 הָאָדָם 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 יָרַד as applied to the falling or sinking of lofty fortifications, see Deu 28:52; Isa 32:19. מָצֹור, compressing or forcing down; hence, as applied to towns, בַמָּצֹור בֹּוא, to come into siege, i.e., to be besieged (Deu 20:19; 2Ki 24:10; 2Ki 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).