R’ Avraham Reuven Hakohen Sofer zt”l (Yalkut Reuveni) would say: “'ומשה אהרן וחור עלו ראש הגבעה' - Why was it necessary to have a team consisting of Moshe, Aharon, Yehoshua, and Chur to fight Amalek? The first letters of the names ‘Aharon,’ ‘Chur,’ ‘Yehoshua,’ and ‘Moshe’ form the acronym for ‘achim’ (אחים) - ‘brothers.’ Moshe’s call to the Jewish people was to act as brothers, live in brotherly harmony, and be united in the study of Torah and observance of mitzvos. This would assure that Amalek would be unable to penetrate the Jewish camp.”
A Wise Man would say: “No person is your friend who demands your silence, or denies your right to grow.”