All of this revelation of divine energy came about through The Giving of the Torah, as the verse concludes “the earth trembled,” meaning that it became submissive. The revelation was so great that the world lost its sense of being separate from Hashem, like a person who trembles before a truly great man and forgets about himself.
This process of revealing Hashem is through the Jewish People. They draw down Hashem’s Light “מִש ֵּעִיר-through a hairsbreadth revelation” which causes that “אֶרֶ ץ רָ עָש ָה -the earth trembled in recognition of Hashem.” When did this happen? “זֶה סִינַי-this happened at Mount Sinai”, as the verse ends, which is when they received the Torah.
However, the angels also asked for the Torah, like it says (Tehillim 8:2) “Give Your glorious Torah to the heavens,” but the Jewish People in that generation merited to receive it through their being enslaved in Egypt with “cement and bricks” (see Shemos 1:14). Through this unwavering faith in Hashem despite extreme hardship the “Sitra Achra-Unholiness” became subdued.
However, every day before learning Torah we make the blessing “Blessed are You Hashem, Who gives us the Torah”, and our Sages say (Pesachim 116b explained in Tanya ch. 47): “Every day a person is obliged to see himself as though he had left Egypt that day.”
Just like 3300 years ago we left Egypt and received the Torah because we subdued our natural inclination, so too every day we experience the idea of leaving Egypt and the idea of receiving the Torah in a new way.
