Sifrei Devarim 203

¹(Devarim 20:19) "If you besiege a city many days": Scripture here speaks of an optional war. ²"a city": and not a metropolis; ³"a city": and not a village. ⁴"many days": "days" — two; "many" — three. We are hereby taught that peace is offered for two days, and a third day for the battle. And even though there is no proof for this, there is an intimation of it in (I Samuel 30:1) "And David and his men came to Tziklag on the third day." Variantly: From here it is derived that gentile cities are not besieged fewer than three days before the Sabbath, (so that the siege not extend into the Sabbath); but if the siege began, it is not interrupted. And a sea voyage is not begun fewer than three days before the Sabbath. When is this so? For a long voyage, but for a short one, it is permissible. ⁵"to war upon it, to capture it ": and not to destroy it. ⁶"You shall not cut down its tree by wielding an axe against it": This tells me only of iron (i.e., an axe blade). Whence do I derive (the same for destroying it by) diverting a water course from it? From "You shall not destroy its tree" — in any manner. ⁸"For from it you shall eat": a positive commandment; ⁹"but it you shall not cut down": a negative commandment. ¹⁰Variantly: "for from it shall you eat": a tree providing life for a man. R. Yishmael reasoned hence: If the L-rd is so solicitous of the fruits of a tree, how much more so of the tree itself! And if Scripture exhorts against (cutting down) a tree, which only produces fruit, how much more so (does it exhort against destroying) fruit itself!