“כִּי יָדַעְתִּי אַחֲרֵי מוֹתִי כִּי הַשְׁחֵת תַּשְׁחִתוּן וְסַרְתֶּם מִן הַדֶּרֶךְ אֲשֶׁר צִוִּיתִי אֶתְכֶם וְקָרָאת אֶתְכֶם הָרָעָה בְּאַחֲרִית הַיָּמִים כִּי תַעֲשׂוּ אֶת הָרַע בְּעֵינֵי יְהוָה לְהַכְעִיסוֹ בְּמַעֲשֵׂה יְדֵיכֶם.”
“For I know that after my death you will surely act corruptly and turn aside from the way that I have commanded you. And in the days to come, evil will befall you, because you will do what is evil in the sight of YHVH, provoking him to anger through the work of your hands.”
Deuteronomy 31:21 “ וְעָנְתָה הַשִּׁירָה הַזֹּאת לְפָנָיו לְעֵד” “the song (שירה) will testify before them as a witness”
Moses knew that after his death, the people will corrupt their ways and he warned them that “The Song” is Malchut that would bring judgments on them.
“יְגַלּוּ שָׁמַיִם עֲוֹנוֹ וְאֶרֶץ מִתְקוֹמָמָה לוֹ.”
“The heavens will reveal his iniquity, And the earth will rise up against him.”
The heaven is Zeir Anpin that only reveals the iniquities, but the earth is Malchut and it will rise with judgments to make corrections for those iniquities.
2 Samuel 22:1
“וַיְדַבֵּר דָּוִד לַיהוָה אֶת דִּבְרֵי הַשִּׁירָה הַזֹּאת בְּיוֹם הִצִּיל יְהוָה אֹתוֹ מִכַּף כָּל אֹיְבָיו וּמִכַּף שָׁאוּל.”
“David sang this song to YHVH on the day YHVH rescued him from all his enemies and from Saul.”
King David elevated and connected Malchut to Zeir Anpin like Moses, but it was only at the end of his life. King David had enemies throughout his life. When we read ‘on the day YHVH rescued him from all his enemies’ we understand that it was at the end of his life when he had peace from his enemies.
Moses’s presence and light guided the people on the righteous path. They had someone to look up to. He knew that after his passing, the people would follow a corrupted way.
It’s common to see that after the passing of a righteous leader, a big void of light created and it is hard for others to fill it. Most of the times, the new leadership becomes corrupted and the old followers of the righteous leader, disperse, seeking another great source of light to ‘lean’ on. Some weak people even lose their faith and connection to the Torah.
When Moses said “the song (שירה) will testify before them as a witness”, he pointed to the Torah as a source of good for those who follow it. If they are not, the Torah would testify that they don’t follow it and the ‘earth’/judgments would rise against them.
Rabbi Shimon was a ‘Holy Candle’ for his generation. He prevented a lot of chaos from manifesting in the world. He knew that after his passing there will be a long period of darkness. Rabbi Yossi in the Zohar tells us that after the passing of Rabbi Shimon, the springs of wisdom will stop their flow and the friends won’t be able to reveal deeper Torah secrets (Vayechi #120 ).
Rabbi Shimon appointed Rabbi Aba to write down the Zohar studies that would be revealed in the last millennia to support the Shechina in her efforts to protect us and to lead us in righteousness to earn merits to live or resurrected into Mashiach.