(31:2) Moses said to them, “Today I am 120 years old, and I can no longer go out and come in. God has also told me that I would not cross the Jordan.”
Today I am 120 years old What is the intent of “today”? Moses meant to say: Today, the seventh of Adar, my days and years are complete, for Moses was born and died on the seventh of Adar. This teaches you that God rounds out the days of the righteous from day to day and from month to month, as it says “I will fill the number of your days” (Exodus 23:26) (Sotah 13b).
I can no longer go out and come in What did Moses mean by “go out and come in”? Do you think it should be taken literally, that he was physically weak? But it says “Moses was 120 years old when he died; his eye had not dimmed, and his vigor had not diminished” (34:7). And it also says that on his final day, “Moses ascended from the plains of Moab to Mount Nebo” (34:1); and we learned: There were twelve steps, and Moses bounded them with one leap! So it cannot mean that he was frail and infirm. R. Shmuel b. Nachmani said: It means that Moses was no longer able “to go out and come in” in the words of the Torah, implying that the gates of wisdom were closed to him (Sotah 13b).