Pesach, or Passover, is the second and probably best known of the three ancient biblical pilgrimage festivals to the sacred Temple in Jerusalem. It occurs in the spring, and it follows by several months the festival of Sukkot, which takes place in the fall immediately after the Days of Awe. Passover is observed during one of the important harvest seasons in the land of Israel, and, for that reason, some scholars have suggested that it may have agricultural roots as much as religious ones.

Yet the Bible itself is very clear that Pesach is not about celebrating a harvest, but rather about celebrating the gift of freedom—specifically, the liberation of the Israelite slaves from their oppression and bondage in Egypt under Pharaoh. In many ways, Pesach celebrates the physical birth of the Israelites as a people, as well as the guiding hand of God, the metaphysical author of this story and ultimate redeemer. Along with Moses, God delivers the Israelites from a place of deep darkness and catalyzes a great spiritual journey. This journey will lead a rag-tag band of ex-slaves into the desert wilderness of Sinai toward their eventual goal, the Promised Land.

According to the Torah, the original week-long observance of Pesach was very simple and entailed only three basic elements, all of which were meant to retell and remember the Exodus narrative. First was the offering of a Paschal lamb to recall the blood that the Israelites put on their doorposts to save them from the angel of death during the tenth and final plague. Second was the consumption of bitter herbs to experience, symbolically, the bitterness of slavery that had played such a pivotal role in their history. Third, and perhaps most famous, was the eating of unleavened bread, matzah. "The Bread of Affliction" was to remind us that the Israelites fled Egypt in such intense haste that they did not even have time to wait for their bread to rise.

After the conquest of Canaan and while the Temple stood, all of these practices could and did take place during pilgrimages to Israel's holy capital, Jerusalem. With a formal religious leadership (the Levites and the Kohanim, or priests) now in place, new opportunities for expressions of praise and gratitude emerged, and additional sacrifices were made. Jerusalem was filled with families, animals, and feasts, making Pesach both a national and a religious event. Yet that all came to an abrupt and violent end when the Romans sacked the city, destroyed the Second Temple, and slaughtered many thousands of people, causing the Great Diaspora in the year 70 A.D.

A great transformation in the Jewish religion was to follow. The spiritual way of life that had been practiced by and was familiar to Jews for centuries was now gone. Rather than falling into oblivion, Judaism reinvented itself. Local synagogues replaced the centralized Temple as the primary institutions for communal worship. Liturgy and fixed prayers began to supplant animal sacrifices and other offerings as the key vehicles for spiritual expression. The rabbinate, a study-based group, replaced the hereditary-based priests and Levites as the new religious leaders of the Jewish people. The rites, rituals, and holidays that had defined Jewish civilization for so long became transportable and, very frequently, centered in the home.

Pesach was no exception. In the post-Temple world, Pesach shifted radically from a mass pilgrimage festival to the Holy Land into a more modest observance that could be shared with a person's family, friends, and neighbors, irrespective of where one lived. Despite this downsize in scope, however, there was an increase in ritual practices and objects associated with the annual event. Under the influence of Hellenistic culture, the traditional Pesach feast became something else, something more complex, substantive, and theological. Following the pattern of the Greek and Roman symposium—a banquet that involved study, discussion, and debate—the early rabbis developed the "Seder." The Seder is an ordered meal with a prescribed set of religious objects and practices, and a text that included verses from the Torah, questions for discussion, commentaries and interpretations, and various blessings.

The text became known simply as the Haggadah, "The Telling," and what it told was the story of the Israelite journey from slavery to freedom. Moses, the central figure, leader, and redeemer in the Pesach narrative, is conspicuously absent from the Haggadah. Most scholars attribute this to a deliberate, somewhat subversive attempt on the part of the rabbis to accentuate the role of God's ultimate providence, and to thus avoid the dangers of potentially, even inadvertently, elevating Moses in the eyes of Jews to the status of a deity—an idea which is anathema to Jewish belief.

One of the most important features of the new Pesach observance was the Seder Plate, a symbolic platter at the center of the table containing several ritual objects. Each object represented a different aspect of the Passover tale: a shank bone (to represent the original Paschal lamb sacrifice); karpas (a green vegetable, usually parsley, to mark spring and renewal); bitter herbs (to symbolize Egypt's bitterness); charoset (a mixture of chopped apples and nuts to recall the mortar used to make bricks for Pharaoh's pyramids); and a roasted egg (to represent a festival offering). Sheets of matzah, of course, were stationed nearby. During the course of the ritual meal, four cups of wine were consumed, and participants were instructed to recline, a sign that they were now truly free and in a place of safety and comfort.

A special, often ornate and beautiful chalice ("Elijah's Cup") was placed in a position of prominence on the Seder table, which never was (or is) touched by human lips. As the harbinger of the messianic era, Elijah is symbolically present at every Seder, an invisible and silent symbol of the future age of freedom, justice, and peace that we are promised will one day arrive. Finally, as with the other two ancient pilgrimage festivals (Sukkot and Shavuot), the recitation of Hallel, or psalms of praise, are offered at the close of the evening.

The Seder—and, by extension, the festival of Pesach—has remained essentially unchanged over the course of nearly two millennia, a testimony to its power.