Arousing the giving of the Torah from below

איתא בזוה"ק דבעי למלעי באורייתא דבע"פ בההוא ליליא.

It is brought in the Zohar HaKadosh that one must labor in the Oral Torah (Torah she'b'al peh) on that night (the night of Shavuos).

The Sefas Emes opens with the Zohar's directive to immerse oneself specifically in Torah she'b'al peh on the night of Shavuos — the basis for the Tikkun Leil Shavuos.

והענין היא דכתיב את ה' האמרת וה' האמירך וע"ש בפי' האבן עזרא בשם ר"י הלוי ז"ל פי' האמרת פעלת המעש"ט שעשית עד שאמר אנכי ה' אלקיך כו'.

And the matter is as it is written: "You have caused Hashem to say (he'emarta), and Hashem has caused you to say (he'emircha)" (Devarim 26:17-18); and see there in the commentary of the Ibn Ezra in the name of Rabbi Yehudah HaLevi z"l, who explained "he'emarta" — you brought about, through the good deeds (maasim tovim) that you did, that He said "I am Hashem your God…"

The reciprocal verbs he'emarta / he'emircha express a two-way relationship. The Ibn Ezra, citing the Kuzari, explains that through Yisrael's maasim tovim they "caused" Hashem to declare "Anochi" — Bnei Yisrael's avodah from below evoked the giving of the Torah.

וע"ז כתיב תנו עוז לאלקים.

And concerning this it is written: "Give strength to Elokim" (Tehillim 68:35).

The pasuk's call to "give strength to Hashem" reflects this same idea — that the actions of Bnei Yisrael below empower, as it were, the revelation above.

וכ' ה' עוז לעמו יתן.

And it is written: "Hashem will give strength to His people" (Tehillim 29:11).

The flow is reciprocal: when Yisrael "give strength" through their avodah, Hashem in turn "gives strength to His people" — the gift of the Torah.

כי בנ"י צריכין לעורר נתינת התורה וע"י זה ה' עוז יתן.

For Bnei Yisrael must arouse the giving of the Torah (an awakening from below), and through this Hashem gives strength.

The giving of the Torah is not one-sided; Bnei Yisrael must first generate an isarusa diltata (awakening from below), and only then does Hashem respond by "giving strength" — bestowing the Torah.

וכ"כ ומשה עלה אל האלקים שהי' התעוררות מלמטה אח"כ ויקרא אליו ה' מן ההר.

And so it is written: "And Moshe ascended to Elokim" (Shmos 19:3) — that there was first an arousal from below — and afterward, "and Hashem called to him from the mountain."

The sequence at Sinai models this order: first Moshe ascended (the awakening from below), and only then did Hashem call to him — the response from above following the human initiative.

ויש בזה סוד שגרם משה רבינו ע"ה בזה יחוד עליון כמבואר כעין זה בזוה"ק כמה פעמים.

And there is a secret (sod) in this, that Moshe Rabbeinu a"h thereby brought about a supernal union (yichud elyon), as is explained in this manner many times in the Zohar HaKadosh.

By initiating the ascent, Moshe Rabbeinu effected a yichud elyon — a unification on high between the upper and lower realms, a recurring theme in the Zohar.

וע"ז איתא בזוה"ק עושי דברו לשמוע בקול דברו:

And concerning this it is brought in the Zohar HaKadosh: "the doers of His word, to hearken to the voice of His word" (Tehillim 103:20).

The Zohar reads this pasuk to mean that the "doing" comes first — the avodah from below — and the "hearkening" to Hashem's word follows; one's own action draws down the ability to truly hear, which is why we learn Torah she'b'al peh on this night.

Summary: Kabbalas haTorah is a reciprocal act: through their maasim tovim Bnei Yisrael "cause Hashem to speak" and arouse the giving of the Torah from below, and Hashem in turn "gives strength to His people." Moshe Rabbeinu's ascent before Hashem's call models this order — "doing" precedes "hearing" — and effects a supernal yichud, which is why we labor in the Oral Torah on the night of Shavuos.