Among the songs with which the first seder concludes is "Vayehi ba-Chatzi ha-Laiylah" ("And It Happened at Midnight"). This song catalogs various miracles and instances of divine revelation which occurred on the night of the fifteenth of Nissan throughout the generations. However, the relevance of this song to the seder and the story of the Exodus is unclear. What element of that story is amplified by enumerating seemingly unrelated events, which occured over a span of hundreds of years? How is our experience of this night enhanced by adumbrating its history?
At first glance, the fifteenth of Nissan, the date of the Exodus, is special owing to its historical prominence; the Exodus endowed this day with its everlasting significance. While this conventional understanding is not entirely incorrect, it is certainly deficient. A brief excursus on the Jewish conception and philosophy of time will provide a fuller understanding of and a deeper appreciation for the uniqueness of the seder night.
Judaism recognizes the duality of time. On one hand, time is quantitative, an instrument for measuring motion. A single day marks one complete rotation of the earth on its axis, a month measures a cycle of lunar movement, and similarly, all units of time are linked to motion (cf. Pesachim 94a, "What distance does an average person cover in a day? Ten parsangs.").
On the other hand, time is also qualitative, possessing inherent qualities. Shabbos, for example, possesses kedushas ha-yom; it is inherently holy, because "God blessed the seventh day and sanctified it" (Gen. 2:3). So too each of the Jewish holidays is distinctively, intrinsically holy. Moreover, it is the unique kedushas ha-yom (inherent holiness) of each holiday which generates that holiday's prescriptions and proscriptions. Thus, for example, the unique kedushas ha-yom of the fifteenth of Tishrei obligates us to dwell in sukkot, and so on.
The kedushas ha-yom of each holiday generates that holiday's spiritual themes and creates its religious opportunities. Consider the following analogy. Within the agricultural cycle, certain periods of the year are especially conducive to planting, others to harvesting, etc. (cf. Berachos 18b). So too within the religious, temporal cycle. By virtue of their inherent spiritual qualities certain days of the year are especially conducive to certain religious experiences. Accordingly, our sages identify the asseres yemei teshuvah (the ten days from Rosh ha-Shanah to Yom ha-Kipurim) as especially conducive to repentance, and in this period repentance is especially efficacious (see Rosh ha-Shanah 18a).
The holiday of Pesach is infused with a kedushas ha-yom of ge'ulah (redemption), and the seder night is singularly suited for experiencing the shechinah (divine presence). This intrinsic redemptive quality of the fifteenth of Nissan is responsible for the timing of all the miraculous events and instances of divine revelation which have occurred on this night. Especially significant are the miracles and incidents of divine revelation which antedate the Exodus because they clearly attest to the innate quality and intrinsic character of the day. The fifteenth of Nissan does not owe its uniqueness to the Exodus; on the contrary, the timing of the Exodus was determined by the intrinsic uniqueness of this day.
The Torah describes the night of the Exodus as leil shimurim -- a night of anticipation. Our sages explain that it is "a night that from the six days of creation has been anticipated" (Rosh ha-Shanah 11b). In other words, at the moment time was created this night was cast as a time of ge'ulah and gilui shechinah.
The song "And It Happened at Midnight" seeks to sensitize us not only to the acquired historical significance, but also to the intrinsic spiritual character of the day. In so doing, it urges us not to be content with passively commemorating the Exodus, but to strive to actively experience the wondrous, wonderful kedushat ha-yom of gilui shechinah.