Rabbi Yaakov Weinberg zt”l: Notes on Devarim VIII: The Spies
We see immediately in pasuk 22 the roots of the Chet HaMeraglim just by the way the people asked to send spies. All of Klal Yisrael, not a portion, said we want to send spies so that we will know which roads to take, how to fight, how to strategize.
In other words, they were saying that we want to fight. If Kavayachol was doing the fighting, need they worry about how to fight the wars?
But they did not want to win the wars through Hashem, they wanted to win naturally. [This is why the gezaira only applied to those who would have gone out to war, from age 20 until 60(see 2:14 ‘anshei hamilchama’). Although the 18 and 19 year olds may have also participated in the crying and complaining but since the issue of going to war with miracles or without wasn’t relevant to them practically then they do not receive the same severity of punishment.]
When you live with miracles, you have to live with the presence of G-d and it is not easy to live constantly with G-d so close to you. They wanted to live a more natural existence with G-d there and helping but without it being too demanding. This is why the meraglim came back and said that the people in Eretz Yisrael are too strong for us.
They meant without the help of G-d they are too strong for us and we will not be able to live in Israel the way we would like to-without miracles and without G-d’s immediate presence.
This is the hesber of why the women did not particpate in the Chet HaMeraglim. Women are more able to live with kedusha when contrasted with men. Men need the feeling of Kochi V’Otzem Yadi- it is my accomplishment(not G-d’s, not a miracle’s)- more than women do.