Filling the Wine Cups Four Times
"Of the many additional explanations offered for this practice of drinking four cups of wine, the most popular is that they are reminders of the four verbs used in the Bible to describe the drama of redemption (Exodus 6:6-7): a) I will bring you out from Egypt; b) I willdeliver you from their bondage; c) I will redeem you with an outstretched arm; d) I will take you to Me for a people."
(The Family Seder. Prepared by Rabbi Alfred J. Kolatch. Jonathan David Publishers, Inc. Middle Village, New York. 1991 by Alfred J. Kolatch)