Exode 19:17

This tells that the Shechinah came toward them as a groom going out ot meet the bride. This is the meaning of: “God came from Sinai” and it does not say: “Came to Sinai.”

And Mosheh brought forth the people from the camp to meet the glorious Presence of the Lord; and suddenly the Lord of the world uprooted the mountain, and lifted it in the air, and it became luminous as a beacon, and they stood beneath the mountain.

לקראת האלוקים, toward the army of angels forming the entourage of the Divine presence, in anticipation of the descent of the Shechinah on the mountain in verse 20.

ויתיצבו, “they stood at attention;” the expression ויתיצבו, as opposed to the normal ויעמדו, for “they stood,” is the reason why our sages said that the mountain had assumed a threatening posture, i.e. they felt that unless they agreed in advance to accept the Torah, they were doomed to die there. (Compare Talmud, tractate Shabbat folio 88). How can we reconcile this with the statement on the same folio that the people by saying: נעשה ונשמע, (Exodus 24,7) “we are ready to accept the laws of the Torah before we have even heard any details” had paid G–d the greatest possible compliment? We need to say that when G–d wanted to give the Torah to Israel, they asked Him how many different Torahs He had at His disposal? He told them that He had both a written and an oral Torah at His disposal. They answered that they were willing to accept the written Torah, but could not promise to accept the oral Torah. As soon as G–d heard this, the mountain began to assume a threatening posture, and they became frightened. (Tanchuma on the portion section 58, paragraph 3) This is what caused the Talmud on folio 88 in Shabbat, to coin the expression that at Mount Sinai the Jewish people accepted the Torah under great moral/psychologial pressure, whereas during the period of Achashverosh, in exile, they accepted it wholeheartedly without any external pressure. (Yalkut Shimoni, Isaiah, second section item 389). G–d is supposed to have wrapped a sword inside the Torah, implying that unless they accepted the Torah they would die by the sword. This is also supposed to be the reason why the prophet Isaiah in Isaiah 1,19, wrote: אם תאבו ושמעתם טוב הארץ תאכלו ואם תמאנו ומריתם, חרב תאכלו כי פי ה' דבר, “if you agree and give heed, you will eat the good things of the earth; but if you refuse and disobey, you will be devoured by the sword.” What occasion did the prophet have in mind when he wrote these words? None other than when the people stood at attention at Mount Sinai. This is also the meaning of a famous liturgical poem in the prayers recited on Shavuot which begin with the words: ראשית עטיפת הזיין צהלה ורנה, [none of these liturgical poems are found in the machzorim in use in eretz yisrael. Ed.]