This week's Torah Portion continues the drama of the Jewish People in the desert. Korach stages an uprising against Moshe, and causes a rift resulting in the earth opening up and enveloping Korach (Moshe's cousin) and his entire entourage. The Torah tells us, "Do not be like Korach and his assembly." This is the source for prohibition against quarreling.
Rav Chaim Shmuelevitz ztz"l has a quite witty yet profound take on this verse. Not that WE should not be like Korach, but that there will never be an argument for the rest of history that is completely one-sided. All other fights after Korach's will, even in a small way, be two-sided.
G-d is teaching us that even if we are correct, it is wrong to fight. Whatever it takes to avoid it - swallowing one's pride or even spending time or money - it is worthwhile. It's part of the cost that we pay for doing what's right!
Have a wonderful Shabbos!