In the beginning of the Parsha, Hashem tells Moses to extract retribution from the Midianites for all that they have done against the Jewish people, and once this is done he will pass away. “Take the vengeance of the Jewish people from the Midianites, then you will pass away.” (Numbers 31:2) The Medrash comments that this is a great lesson in serving Hashem, even if it involves tremendous of sacrifice. Moses knew that he wouldn’t die until he waged war with the Midianites if he wanted to push off his death by twenty or thirty years, he could have just delayed the battle with the Midianites. Instead, he said, “We have no right to push off fulfilling Hashem’s will.” Immediately he sent out the Jewish soldiers to wage war against the Midianites.
Our sages tell us that the soldiers refused to go to battle. They knew that Moses would die once the war was over, and didn’t want to hasten his death. Moses forced them to go. The lesson Moses taught us was very powerful. We’ve got to grab every opportunity that presents itself to do a mitzvah, regardless of what seem to be adverse personal consequences.
Rav Leib Chasman explains, that the lesson of this incident goes one step further; who led the Jewish people in this battle? The Torah tells us that Moses sent Pinchas and Eliezer the Priest to lead the Jews to battle. Why didn’t Moses go himself, as he did during the battles with Sichon and Og? The Medrash explains that since he grew up in Midian, it would not have been proper gratitude for him to wage war against them.
Astounding!! A battle that was so important to wage, that Moses was willing to end his life to start it; but he couldn’t lead it if it would reflect a lack of gratitude.
These are two great lessons that Moses taught us as he prepared to die; the commitment to do whatever G-d instructed, regardless of the consequences; secondly, the absolute commitment to always exhibit gratitude to anyone who helped us in any way.