So get this. According to some Jewish interpretations, God lifted up and suspended Mt. Sinai over the Jewish people and warned them that if they did not accept the Torah, He would drop the mountain on them.

That's absolutely wild.

Putting aside for now the question of Scriptural support for this interpretation, we might ask why it would have been necessary for God to do this.

Here are some of the reasons I came across:

1) The Torah consists of two parts, the Written and the Oral. The Jewish people were ready to accept the Written Torah, but not the Oral Torah. To persuade them, God held the mountain threateningly over them.

2) When God offered the Torah to the Jewish people, He told them of the various positive commands (mitzvot) and negative commands. In addition to performing the mitzvot, it is also necessary to study Torah diligently and assiduously.

When the Jews said “Na’aseh venishma” (We will do and we will listen) it referred only to meticulous observance of the mitzvot but not to toil in the study of Torah. For this God had to suspend the mountain over them to force them.

3) Prior to God giving the Torah to the Jewish people, Moses was instructed to tell them the great benefits for their accepting the Torah. Accepting the Torah for the sake of receiving a reward though puts them into the category of a servant who serves his master for the sake of receiving a reward, as opposed to accepting it even without any anticipation of reward.

To elevate them to that higher level, God suspended the mountain over them to force them to accept it, and that represented strict submission to His will.

4) A Jew’s service of God must be out of ahavah — love — and yir’ah — fear. The acceptance of the Torah was an acceptance out of love. Love, although essential, is insufficient by itself and therefore cannot be the only motivation. There had to be an acceptance out of fear as well.

To this end, holding the mountain over the heads of the Jewish people was necessary to instill in them a way of service in which love and fear combined together.

5) Originally when the Jews were offered the Torah they agreed to accept it on their own volition. They consented to obey Torah directives as people who are not commanded but who nevertheless perform mitzvot. They calculated that in this way they would receive the maximum reward.

The reason God forced them to accept even after they had already done so is because of the belief that “One who performs a mitzvah having been commanded to do so is greater than one who performs a mitzvah voluntarily, without having been commanded to do so.” Why?

Well, one who is obligated is more worried and anxious lest he not fulfill. Also, the yeitzer hara (a term for man's congenital inclination to do evil)  makes a greater effort to deter the commanded person from doing the mitzvah. Since it would be more difficult for him to perform the mitzvah, his reward is greater.

6) In the wilderness all the needs of the Jewish people were provided for. Under such conditions, there was absolutely no reason not to adhere to the teachings of the Torah. By placing the mountain over the people, God was asking them a question:

“There is no guarantee that the tranquility you are currently experiencing will last forever. How will you conduct yourselves when problems befall you? When you will experience difficult times and your very existence is threatened, will you still keep the Torah?”

“If you have any doubts,” God told them, “You should know that it is to your advantage to keep the Torah under all circumstances. For as soon as you forsake the Torah, that will be your burial.”

We as Christians don't put much stock in the legend itself, but it's pretty interesting nonetheless!