
Divrei Torah Parshas Vayelech
based on a ma'amar by the Divrei Yisrael in Ashei Yisrael, Parshas Vayelech
"He [Moshe] said to them [the Jewish People], 'I am 120 years today, I can no longer go and come...'" [Devarim, 31:2]
Our Sages tell us that one mitzva draws another mitzva [Pirkei Avot, 4]. The Divrei Yisrael explains how this works, in the case of tzaddikim who are attached to Hashem and His Torah. For example, one who is engaged in Torah study, can become so engrossed in it that he cannot budge from it, except by remembering the sweetness of Tefilla [prayer]. This enables him to cease learning and go to daven. Similarly, in the midst of Tefilla with dveykus [attachment to Hashem], one can feel that "halevai - if only - I could daven all day long." Then it's impossible to budge from it, except by remembering the sweetness of Torah study.
Or, while sitting in the Sukka, absorbed in the pleasantness of the mitzva, it's impossible to leave it, except when the time for Tefilla comes. Then the sweetness of Tefilla appears before his eyes, and he can leave the Sukka to go to shul and daven. This becomes a cycle - from the Tefilla in shul to the mitzva of Sukka, and back to shul, and so on.
So it is with the tzaddikim, with each mitzva they are engaged in, the sweetness of the other mitzva draws them to engage in that mitzva. This, then, is the explanation of the teaching, "one mitzva draws another mitzva", cited above.
Now we can understand our verse as well. Moshe says, "I am 120 years today," as the verse [Tehillim, 104:29] says, "their spirit increases when they expire." That is, tzaddikim achieve an enhanced spirit of Kedusha [holiness] when they expire, clinging to the Divine Presence [Shechina], which is truly impossible to depart from. So at this point Moshe could "no longer go and come," from one mitzva to another, for there is no sweetness greater than the attachment to Hashem at the time when the soul has its "spirit enhanced."
Translated by Reb Yitzchak Dorfman of Yerushalayim, a Modzitzer Chassid