Yitro: Aliyah 5

The 5th Aliyah in Yitro gives us the number 3 again. However, this time instead of 3 months, we are told that the Jewish people must prepare themselves and remain clean for a 3 day period.  This instuction  is repeated 4 times in the Aliyah, and not mentioned again outside of it.

First Gd tells Moshe to have the people clean themselves, Today and Tommorow, and on the Third day they should be ready, because on the Third day Hashem will show himself.  (third day is said twice in the same verse)
Then Moshe tells the people to refrain from being with their wives for 3 days.
Then the Torah tells us that third day comes and Gd shows himself.

The first 2 mentions of the number three, tells us that even though the Torah will keep the Jewish people eternal, it's not always going to be good and happy. We will have negetive times, and things won't be great. Such as when the Tablets need to be given a second time, or when the Jewish people lose 2 temples, or when there is division amongst the Jewish people themselves and we split into two kingdoms.

The third time 3 is mentioned, is when we are told that there is a separation between the men and the women.  This is like the book Shir Hashirim, where the Jewish people and Gd are compared to two lovers.  Though it may seem that they are separated always, really there is always a chance to come back and be united.

The 4th time is when the promise of an eternal relationship is made concrete, like the 4 elements of the world, or the 4 corners of the Earth.  The people hear Gd speak, and hear the first of the commandments and the miztvot and the Torah that will keep us eternal.  As long as the Earth exists, so will the Jewish people.