The passuk states that Moshe Rabbeinu said, “I am 120 years old, I am not able to go out and to come in and Hashem said to me ‘you will not pass through the Yarden.’”
Rashi is bothered: the passuk states in V’zos HaBracha לא כהתה עינו ולא נס לחה, Moshe Rabbeinu’s eyes did not weaken, and his freshness didn’t leave. He had his complete strength to bring in and take out the nation. Yet here the Torah states “I am not able…?”
Rashi answers that Moshe said, “I do not have permission to cross the Yarden because Hashem took away my authority and gave it to Yehoshua.” The ו’ ofוה’ אמר אלי לא תעבר את הירדן הזה “and” Hashem said you will not pass through the Yarden, is a reason and means because; I am not permitted to continue leading you and bring you into Eretz Yisrael because Hashem said.
The Re’eim is bothered that a ו’ is not generally used to mean because. Rashi therefore brings another explanation: Moshe Rabbeinu was unable to have discussions in the Torah, because the tradition and well springs of Torah were hidden from him. The Ramban explains that this was a miracle so that Moshe should not be disturbed about giving over leadership to Yehoshua. The Sifsei Chachomim adds that Moshe would feel that without the wellsprings of Torah what is the purpose of life?! Moshe said, “Since the Torah was taken from me, I am unable to continue to lead the nation.”
The passuk ends “and Hashem said you will not pass through the Yarden.” The Maharsha explains that Moshe said: do not think that since we are going into Eretz Yisrael which Chazal say אוירא דארץ ישראל מחכים, the air of Eretz Yisrael makes a person smart, therefore I will re-attain my wisdom. Rather, Hashem said to me that I shall not pass through the Yarden; therefore I will not be able to continue to lead you. We see from the Maharsha that had Moshe been able to enter into Eretz Yisrael he indeed would have re-attained the wisdom which he lost. The atmosphere of Eretz Yisrael brings a person to grow in ruchniyus and wisdom.
Fortunate are the Yidden living in Eretz Yisrael who are able to attain high levels and may all of Klal Yisrael merit this with the geula shleima במהרה בימינו אמן.