Three major events occur in Sefer Shmot. The first is yetziat Mitzrayim, followed by matan torah, and finally, the construction of the mishkan. As the events of Sefer Shmot unfold, the bond between Benei yisrael and Hashem grows and develops. This relationship undergoes three specific stages of development, as the above the three events occur.
Rambam in Hilchot Teshuvah in describing the epitome of ahavat Hashem states that it is as powerful as the love between a husband and wife. the theme of Shir HaShirim, which appears to be a love song, is actually the highest expression of ahavat Hashem. Using marriage as a model we can understand the development of the events in Sefer Shmot.
The Jewish process of marrying is comprised of three distinct stages. The first stage, known as kiddushin or erussin - betrothal - is the legal symbolic act of commitment that declares the couple "married" even though at this point the husband and wife are not permitted to one another. From here each one returns to his and her parents home awaiting the culmination of the marriage ceremony. (Due to technical reasons, contemporary practice is to combine this first stage of kiddushin - accomplished today by giving a ring- with the completion of the marriage ceremony. Yet in halachah kiddushin and nissuin are distinct events.)
The second halachic stage of marriage is nissuin. There is a dispute whether this is accomplished by standing under the chupah or being together in the yichud room. It is after nissuin that the husband and wife become permitted to one another and at this point the mutual marital obligations set in.
Following nissuin the third stage begins in the form of the week of Sheva Berachot - the joyful formal beginning of the couple's married life.
The three stages of development that took place as Benei Yisrael became Am Hashem correspond to the processes by which a man and woman are transformed into a happy married couple. Yetziat Mitzrayim is described by Yirmiyahu as the time of "ahavat kelulotayich" - the love of a bride. Yetziat Mitzrayimi was the kiddushin between Hashem and Benei Yisrael , the initial commitment in the process of becoming am Hashem. This commitment was finalized by kabbalat hatorah - the moment of nissuin at which point Benei Yisrael became obligated to fulfill Hashem's will, and in turn, Hashem "obligated" Himself to His nation. This parallels the way in which a husband and wife become responsible for one another at the moment of nissuin.
Following kabbalat hatorah, is the building of the mishkan, a dwelling for the shechinah, The Ramban on the parshah explains that the primary purpose of the mishkan was to insure that the maamad Har Sinai experience would be everlasting. For this reason the central feature of the mishkan is the aron containing the luchot. A couple becomes one at nissuin, under the chupah or through yichud - symbolic temporary homes. These temporary dwellings become permanent during the week of Sheva Berachot as the couple begins life together in a permanent setting.
This development of our relationship with Hashem was not merely an event of the past. Every year as we celebrate the shalosh regalim we relive theseexperiences. We are chosen by Hashem to be His bride during the yom tov of Pesach. We eagerly await our wedding which takes place on Shavuot. Finally, we celebrate our week of sheva berachot during Succot as we recreate the mishkan and the Clouds of Glory.
Each of the yomim tovim has a central theme. The essence of Succot is joy. Although there is a mitzvah of simcha on the other regalim, only Succot is defined as zeman simchatenu. On Pesach our joy is not complete because we have been chosen by Hashem but have not experienced dwelling with Him. On Shavuot we join Hashem at our "wedding", but the chupah of Har Sinai is only temporary. On Succot we celebrate life after the wedding. The true joy of marriage follows the wedding and is felt as the couple lives and grows together. The Binyan HaMishkan of old and the annual Succot are the true times of joy. It is only at these points that our relationship with Hashem has become permanent and this is our ultimate reason for rejoicing. May we merit to soon see the Binyan Beit HaMikdash, the culmination of our eternal relationship with Hashem.