During the Seder, each participant drinks four cups of wine to recall the four expressions of redemption mentioned in the Bible (Ex. 6:6-7).
God tells Moses to tell the people of Israel, “I will bring you out from under the burdens of the Egyptians, and I will rid you from under their bondage and I will redeem you with a stretched out arm and with great judgments: and I will take you to Me for a people and I will be to you a God.” The four cups at the Seder represent the four expressions of redemption–bring, deliver, redeem and take.
The first cup is called the cup of sanctification; the second, the cup of judgment; the third, the cup of redemption; and the fourth, the cup of the kingdom.
A fifth cup was later added by rabbis, called the cup of Elijah. The custom of filling a fifth cup of wine for Elijah the Prophet at the seder table is relatively recent. Some families set a place at the table for Elijah and pour into a goblet called “Elijah’s cup” to symbolize Elijah would be a welcome guest at the seder (Elijah never died. He ascended to heaven). Another custom is to open the door during the seder for Elijah, symbolizing bringing the Messianic age into their lives. Elijah is expected to return at Passover time as we can deduce from Matthew 11:7.
During Passover, no food with leaven is permitted. Leavening is a fermenting process in which yeast turns the food sour. The rules of leavening apply to food prepared out of any of the five kinds of grain; barley, wheat, rye, oats, and spelt.
Although wine is fermented, it doesn’t enter into the category of leaven because itÿs not made from one of these five types. Some reports indicated that possibly unfermented “raisin-wine” was the only acceptable beverage for Passover. Today only kosher wine is used for Passover (Sarna 1988).