What is the meaning of "v'Lo Kamah Od Ru'ach b'Ish?
Zevachim 116b, cited in Rashi: A man cannot have an erection. 1
Radak: Every man's heart (spirit) fell.
Radak citing Targum Yonasan: There does not remain spirit in a man.
Malbim: Normally, when a nation comes to destroy lands, when people first hear, they fear, but when the nation gets close, men arouse each other to fight against the nation. Here, our hearts melted, and also now that you are at the border, no man has a valiant spirit to arouse the people to fight; they all despaired. 2
Zevachim 116b, cited in Rashi: She knew this, for every officer had Bi'ah with her. She was 10 when Bnei Yisrael left Egypt, and was Mezanah all 40 years that they were in the Midbar.
They chased after the Meraglim because they were only two, but they would be too afraid to chase after the nation. All this changed after Achan took from the Cherem. (PF)