Looking to better understand if, per the sources, Moses was at fault for sending spies, especially as it relates to sending them on a seemingly military mission.
Rashi - says that according to your own judgement: I do not command you, but if you wish to do so send them.
שלח לך. לְדַעְתְּךָ, אֲנִי אֵינִי מְצַוֶּה לְךָ, אִם תִּרְצֶה שְׁלַח; לְפִי שֶׁבָּאוּ יִשְׂרָאֵל וְאָמְרוּ נִשְׁלְחָה אֲנָשִׁים לְפָנֵינוּ, כְּמָה שֶׁנֶּאֱמַר "וַתִּקְרְבוּן אֵלַי כֻּלְּכֶם" וְגוֹ'
Ramban says that based on Rashi it would seem that Moshe sinned by sending the Meraglim. However at the end the Ramban says it was not a sin on Moshe's part as Hashem said he may send them.
The mission was itself a direct order from Hashem: וידבר ה' אל משה לאמר שלח לך אנשים ויתרו את ארץ כנען The Lord spoke to Moshe saying, Send out for yourself men and they will scout the Land of Canaan... (Bamidbar 13:1-2) In fact, the Kli Yakar says that לך means for Moshe's benefit:
לפי שאמרו ישראל (דברים א כב) נשלחה לפנינו אנשים ויחפרו לנו את הארץ. לנו היינו להנאתנו ולטובתינו, ואמר הקב"ה למשה שלח לך, ולא להם כי לך דווקא יהיה השליחות להנאה ולטובה אבל להם לא יהיה השליחות לטובתם כי ע"י שליחות זה נגזרה עליהם מיתה ולמשה גרם שיהיה חי עוד מ' שנה, כי כבר נגזר על משה שלא יראה את העשוי למלכי ז' אומות וע"י חטא המרגלים נשתהו מ' שנה
Since Israel said (Devarim 1:22) "We will send before us men and they will search out the Land for us": For us is for our benefit and for our good, and G-d said to Moshe "Send for you," and not for them because specifically for you will the mission be a benefit and a good; but not for them, because through this mission death will be decreed upon them and Moshe would incidentally live 40 more years (because it had already been decreed on Moshe that he would not witness what would happen to the kings of the Seven Nations, and through the Spies they would wait 40 years).
While Rashi explicitly says that לך means that this was not a commandment from Hashem and Moshe was therefore acting of his own accord, Kli Yakar's usage of לך for a different purpose suggests that he does not agree with this perspective. The inference that is it was a commandment in the full sense of the word, and that, although the benefit is incidental (see K"Y above), the mission still benefited Moshe rather than faulted him.
The Ohr Hachaim offers two possibilities why not to fault Moshe for the debacle of the spies.
- Moshe innocently thought that they were on an mission to find hidden treasures in Eretz Canaan and had no idea what the spies true intentions were.
- Moshe knew very well what the spies intended to do but since Hashem allowed them to proceed, it wasn't his place to "outsmart Hashem" and prevent it.
One explanation given in the Rishonim is that Moshe saw which way the winds were blowing...
The Sifre says they came "Barvuviya"; an unruly crowd with the younger people pushing the older ones etc. to ask about sending spies. Looking at the situation he realized that they weren't really committed to going to Eretz Yisroel and were actually looking for some excuse to delay or get out of it.
He felt that is would be better if they refused to go to Eretz Yisroel because of a bad report given by the spies (which was sure to be coming) than they find some non excuse as the latter option would make them much more guilty.
Another explanation (or observation) givin in the Rishonim is that they were never told to be MERAGLIM. In Parshas Shelach it says שְׁלַח לְךָ֣ אֲנָשִׁ֗ים וְיָתֻ֨רוּ֙ אֶת־אֶ֣רֶץ כְּנַ֔עַן . The entire Parshas Shelach only uses the word יָתֻ֨רוּ֙ or some variation of it when describing their mission.
The word יָתֻ֨רוּ֙ in Tanach is used for looking for the good and the way to set it up. Meragal implies spying for the weakness of a place. Moshe told them to do the former. They choose to do the lattar
In Michtav Mei'Eliyahu, vol. 1 p.187, [R' Dessler] has an absolutely brilliant analysis explaining the mistake of Moshe and the Jewish people in sending spies. I can't do it justice here, but he says (based on Rashi that Hashem said שלח לך לדעתך) that Moshe was tested as to the line between necessary and unnecessary hishtadlus. : https://en.wikipedia.org/wiki/Eliyahu_Eliezer_Dessler