As is well known, the concept of Redemption came into being with the Exodus from Egypt, and it was then too that a conduit was opened for the coming of the future Redemption. Since the same downward flow of Divine energy is aroused afresh every Passover as it was at the time of the Exodus, it is obvious that every Passover the radiance of Moshiach is aroused and afresh.(From Exile to Redemption)
(L'Chaim)