Inner leaders bound within the collective

כל נשיא בהם.

"Every one a prince among them" (Bamidbar 13:2).

The Torah commands that the spies sent to scout Eretz Yisrael each be a "nasi" — a prince or leader. The Sefas Emes notes a grammatical nuance in the phrasing.

מהם הול"ל.

It should have said "of them" (meihem).

The verse says "a prince among them (bahem)" rather than the more expected "a prince of them (meihem)." This shift in wording calls for explanation.

גם היו נשיאים אחרים נחשון וחביריו.

Also, there were other princes — Nachshon and his colleagues.

The men chosen as spies were not the only nesi'im in Israel; the established tribal princes, such as Nachshon ben Aminadav, were a different group. So why were these particular men called nesi'im?

אך יש נשיאים מלבר ונשיאים מלגאו וכאן היו צריכין לשלוח אנשים להיות מעשיהם כמעשה כלל ישראל ממש וז"ש כל נשיא בהם כנ"ל:

But there are princes "from without" (mil'var) and princes "from within" (mil'gav), and here they needed to send men whose deeds would be exactly like the deeds of the entire klal Yisrael; and this is the meaning of "every prince among them," as above.

The Sefas Emes distinguishes two kinds of leaders: outer leaders, who lead from above and stand apart from the people, and inner leaders, whose greatness lies in being fully bound up within the collective. For the mission of the spies, Hashem wanted the second type — men whose every act was identical to and absorbed within the deeds of all Israel. That is why the verse says "a prince bahem — among them," indicating a leadership rooted within the klal rather than above it.

Summary: The unusual phrase "every prince among them (bahem)" rather than "of them" teaches that there are two kinds of leaders — outer leaders who stand above the people, and inner leaders whose greatness is being wholly bound within the collective. For the mission of the meraglim, Hashem chose this second type: men whose deeds were entirely identified with the deeds of klal Yisrael, leaders from within rather than from without.