What are the ramifications of "Lo Sechayeh Kol Neshamah"?
Ramban: Refer to 20:10:2:1*.
Rashbam: Once Yisrael come to fight with the Cana'ani nations, it is a La'av against offering them peace-terms. 1
See Oznayim la'Torah, who explains in detail why the Cana'anim needed to be exterminated and why Hashem commended specifically Yisrael to do it.
To whom does "Lo Sechayeh Kol Neshamah" apply"
Rashi in Sotah, 3b: It applies to the seven nations - the Chiti, the Girgashi, the Emori, the Cana'ani, the P'rizi, the Chivi and the Yevusi (men women and children).
How did they kill them?
Sanhedrin, 67a: By the sword (as the Torah writes in Bamidbar, 21:24, in connection with Sichon - Va'yakeihu Yisrael L'fi Charev". 1
See Torah Temimah, note 51.
"Lo Sechayeh Kol Neshamah". How can we kill innocent children who have done us no harm?
R. Bachye (on Pasuk #10): a. It is a Divine decree, whose reason we do not know; b. Since Hashem has negated the power of their angel in Heaven, 1 killing them is like killing a dead person; 2 c. Because they are a branch of a bitter root (which is bound to grow into a bitter plant and cause much harm to their surroundings. 3 And it is normal and perfectly logical to cause a minor damage to avert a major one. 4
Oznayim la'Torah: Because after they had sinned for four consecutive generations, Hashem declared them evil to the core and that they had to be destroyed. 5
R. Bachye: As Hashem said to Nevuchadnetzar when he came to destroy Yerushalayim ?You are grinding flour that has already been ground! You are killing a dead lion! You are burning a burned city!'
As the Navi writes in Chavakuk 1:6 ?that bitter and impetuous nation". See R. Bachye who elaborates and cites Yeshayah 14:21 - in connection with Nevuchadnetzar King of Bavel - "Preparea slaughter for his sons for their father's iniquity; Let them no arise and inheit the lnd, lest the world becomes full of enemies!"
See R. Bachye on p.372 who elaborates.
See Oznayiim la'Torah who elaborates.
Having already commanded, in Sh'mos, 23:33 "Lo Yeishvu be'Artzecha Pen Yachti'u oscha Li", why does the Torah need to repeat here "Lo Sechayeh Kol Neshamah"?
Ramban (in Pasuk 18): Because, whereas the Pasuk in Sh'mos is referring to the seven Cana'ani nations in general, the Pasuk here is coming to add a La'av against allowing even individual Cana'anim to remain alive to serve us, in case they prevail upon us to worship their idols.
