Beshalach Likutei Sichos – Vol 21 p 77 ff Exile and Redemption (138)(01) Class One.Moshe was fatigued and he needed physical support to keep his hands raised, so the Yidden would win.He is considered mistaken in not attacking Amalaik himself (and right away) and instead sends Yehoshua (the next day).

Beshalach Likutei Sichos Vol 21 p 77ff Exile and Redemption (138)(02) Class Two.Continued.Moshe’s mistake was calculating reasonably what is the right thing to do, rather than acting.

Beshalach Likutei Sichos Vol 21 p 77ff Exile and Redemption (138)(03) Class Three.The lesson: having Mesiras Nefesh even for “the worst Jew”.