Or HaChaim on Numbers 11:15/אור החיים על במדבר י״א:ט״ו

1 ואם ככה את עשה לי, "but if You will deal thus with me, etc." Moses was afraid that G'd would say to him that he must continue to carry this burden even against his will as it is the fate of a servant of G'd that he continue to serve his G'd until he dies, as we know from Deut 6,5 where we are commanded to love G'd with our entire soul, i.e. even if we have to die in the process. This is why Moses said: "if that is my fate then please let me die now." He added that the reason he asked to die now was so that he would not be a witness to his own failure as a leader. Moses was afraid that if instead of G'd letting him die the people would kill him for not providing meat, he would become the cause of their becoming guilty of murder. Their punishment would be that they would be wiped out by G'd. He, Moses, would much rather die now than for Israel to become guilty of such a crime. Solomon expressed such a thought in Proverbs 17,27 when he said: "it is not good for the righteous to become the cause of retribution."

2The reason Moses repeated the words הרגני נא הרוג, was that he was certain he would meet with death either at the hands of G'd or at the hands of Israel. If G'd were to kill him now, therefore, He would only be taking the life of a person who was already dead for all practical purposes. In order to interpret the verse in this way the word harog must be read as harug. Yalkut Shimoni item 735 on our verse expresses it thus: "If I do not give them meat they will kill me; on the other hand, if I oppose You (by speaking against You) You will be forced to kill me." The wording of our verse can tolerate all these various interpretations.