What did the spies mean when they said "Lo Nuchal La'alos el ha'Am"?
Ramban: They meant that it would be impossible to attack them even if they were to come and fight them in the field, how much more so to fight them in their fortified cities.
Seforno: ?We will not be able to enter the land?, ?because they will rise against us and prevent us from from entering? ? as occurred immediately after they sinned. 1
Oznayim la'Torah: Following Calev's statement "Aloh Na'aleh ... ", which he said because the conquest of Cana'an was destined to begin with an ascent up Har ha'Emori, 2 they responded by arguing that, he fact, in addition to their superior strength, the Emori had the advantage of height, rendered the entire project doomed to failure.
What did the spies mean when they said "Ki Chazak hu Mimenu"?
Ramban, Targum Onkelos and Targum Yonasan: They were simply stating that the Cana'anim were stronger than them (and it was therefore impossible to defeat them). 3
Sotah, 35a: This is an expression of blasphemy - 'The onwer of the land is unable to remove his vessels from it!', meaning that Hashem is incapable of removing the Cana'anim from His land.
Refer to answer #3. See Oznayhim la'Torah, who connects this with the Mishnah in Avos, 2:4 'Al Ta'amin be'Atzm'cha ad Yom Moscha' and elaborates.
See Sifsei Chachamim. See also Ba'al ha'Turim.
Ramban: In answer to Moshe and Calev's previous statements, they now stated what they really had in mind all along - which until now, they had only hinted.
