Rashi tells us that the phrase, “b’etzem ha’yom ha’zeh,” “on that very day,” is mentioned in two other places. When Noach entered the Teivah, Ark, the Torah writes that he entered “on that very day”(Bereishis 7:13). Also, when the Jews left Egypt, the Torah writes that they left “on that very day” (Shemos 12:51). The reason for emphasizing when they left and when Noach entered the Ark, is to demonstrate that even if the people would have said, “We will not let Noach leave; we will not let the Jews depart Egypt,” Hashem enabled them to leave in the middle of the day, when everyone was around, and no one dared — or was able — to prevent them from leaving. Likewise, the Jewish People might have thought that since Moshe Rabbeinu had done so much for them — he led them out of Egypt, split the Sea, brought down the manna and the quail, raised up the well and gave them the Torah — they would not let him “leave.” Consequently, Hashem took Moshe from This World in midday to demonstrate that no human being had control, only Hashem.
The question is obvious: How are we to compare Moshe Rabbeinu’s death to Klal Yisrael’s departure from Egypt and Noach’s entering the Ark? Those two events would have been preventable with sufficient strength and power. Moshe’s death, however, could not have been halted in any way. When his time had come, it had come and we could have done nothing to prevent it from occurring. So what does Rashi mean? Furthermore, what does Rashi mean when he says the Jews might say, “A man who led us from Egypt, etc. cannot be allowed to die” What does Moshe’s role in the Exodus have to do with his continuing to live? Certainly, they understood that it was Hashem Who took them out of Egypt, Who controlled nature and split the sea and fed them in the wilderness. What was Moshe’s role in this?
Horav Chaim Shmuelevitz, z.l., gives a penetrating response which focuses upon our responsibility to acknowledge and pay gratitude to those who benefit us. Klal Yisrael presented a powerful reason for Hashem to keep Moshe alive. After all, he was the individual who had done so much for them. In his merit, Klal Yisrael was alive and miraculously had been sustained throughout forty years of wilderness travel. The amount of gratitude the Jewish people owed Moshe was immeasurable. If so, Hashem had to keep him alive when Klal Yisrael prayed on his behalf. Their obligation to him was overwhelming. This was reason enough for him to live.
Indeed, this is what Eliyahu HaNavi said to Hashem when he prayed on behalf of the Tzarfati’s son: “How can You take the life of the son of the widow who provided me with a place to lodge?” Eliyahu owed the widow so much. He was obligated to repay her. Since he owed her – Hashem had to allow her son to live. If the middah, character trait, of hakoras hatov has the ability to bring someone back to life, as it did with the Tzarfati’s son, it likewise should have the capacity for preventing Moshe Rabbeinu’s death. Hashem had no other recourse. He wants us to be makir tov to Moshe – so He had to allow him to continue living.
A compelling reason, an excellent argument, but it was not enough. Hashem had other plans. Moshe’s time to leave This World had arrived. “B’etzem ha’yom ha’zeh, “on that very day,” he was to take leave of his earthly abode – because this is what Hashem wanted.