1)
How will we reconcile "ve'ha'Taf in this Pasuk with the previous Pasuk which wrote "Vehikisa es Kol Zechurah L'fi Charev"?
1.
Rashi: The former Pasuk is discussing adults exclusively.
2)
How will we reconcile the current Pasuk with "Lo Sechayeh Kol Neshamah" in Pasuk 16?
1.
Rashi (in Pasuk 10): The current Pasuk is discussing Milchemes ha'Reshus (a battle involving other nations), but not a Milchemes Mitzvah, as the Torah indicates in Pasuk 15. 1
1
Refer to 20:10:2:1*. See also Rashi in Tehilim, 106:34 and refer to 20:19:3:1*.
