Parshas Vayelech contains one of the grimmest moments in the Torah.
Sefer Devarim has seen some dreadful curses, but no moment in the Torah is quite as deflating as G-d's declaration that the Jews would sin and that G-d would forsake and hide from them, and then when the Jews would realize that they had done wrong and say, Ki Ein Elohai Bekirbi, Because G-d is not among us, Motzuni Haraot Haeleh, these things have come upon us. (Devarim 31:17).
And instead of welcoming back his people, G-d responds with, "And I will surely hide my face on that day."
That's the opposite message of the Shabbos Shuva drashos of so many Rabbis delivered on the Shabbat between Rosh Hashana and Yom Kippur. It's far away from all the assurances that G-d is only waiting for us to return, to take the first step and be welcomed and forgiven.
It seems hopeless.
To understand it though, let's take a step back. Parshas Vayelech is foremost about the Torah. The Torah rarely discusses itself. It exists foremost in an oral mode. Only occasionally in Devarim do we hear mentions of the process by which the Torah that we know came to us.
Why is the Torah necessary? Why do we even need it at all?
Devarim marks the twilight of the life of Moshe. G-d's greatest prophet is attempting to transmit his experience of revelation to us. He is doing that because future generations will experience diminishing levels of revelation. Those Jews who lived in Moshe's time would feel, in the future, as if G-d had hidden his face from them.
What is the origin of the Torah? There is a mass revelation at Mount Sinai. The Jews experience G-d speaking directly to them. And then G-d withdraws.
What is the Torah? The Torah is the result of Ein Elohai Bekirbi.
If there is total and open revelation, then there is no need for recording and codifying the revelation. Even in Moshe's time, it was possible to ask him a question about Halacha, as the daughters of Tzelafchad did, and Moshe would then forward the question to G-d and get an answer.
But without that degree of revelation, the Torah becomes necessary.
We tend to assume that G-d's reply of Anochi Haster Aster, I will surely hide, is a worsening of the condition. But this is not an impenetrable hiding. One example is Megillat Esther in which G-d is "hidden". But not so hidden that we cannot figure it out. Instead we are meant to seek G-d and find Him. Where do we seek G-d out? We cannot climb up Sinai, as Moshe did, after the tablets were broken. G-d is hidden in the Torah. The Torah is our treasure map to finding G-d.
By finding G-d, we atone for having pushed Him away. G-d is not distancing himself from the Jewish people. While they insist Ein Elohai Bekirbi, G-d is actually hiding among them through His word.
When they recognize that He is absent, He draws nearer to them and hides close to them in the Torah.
The song of Haazinu, like the rest of the Torah, is the encoded revelation of G-d. It is where we can find Him. It gives us the path of repentance and revelation for returning to G-d.
We describe the Torah as an Etz Chaim, a Tree of Life. The first tree of life in the Torah though is the one in the Garden of Eden. It's a mysterious entity. All we know about it is that G-d says that if man eats from it he will live forever, and he is driven out to avoid that from happening, and the Garden is then guarded by an angel with a sword.
But the Tree of Life was restored to man through the Torah. While Adam was prevented from eating of it, man today may eat of it and live forever. It is not a mere physical immortality. It is spiritual immortality. The Torah made the Jewish people immortal to the extent that they, not merely eat of it as Adam might have, but to those that grasp it (Mishlei 3:18) and make the commitment to it.
G-d, paradise and immortality, the original things that man lost, are still available to him, encoded in the Word of G-d. The secret treasure of the universe is there waiting for us. All we have to do is look.