“Next Year in Jerusalem” is a regular ritual toast at the Jewish holiday of Passover, during the Passover sedar (dinner) which is filled with specific rituals.
It is a wish/prayer that Jerusalem will once again be the home of Jews, and that Passover will be celebrated there “next year.”
Israel was proclaimed a state in 1948. During Passover that year, the Seder toast was, “Next year in Jerusalem - the Delivered!”
Took a while, but they did it. Tomorrow is the icing on the cake - finally!
At the end of the Passover seder (ritual dinner), the participants all joyously utter "L'Shana Haba'ah B'Yerushalayim!" -- "Next year, may we be in Jerusalem!" This is a wish that this will be the last Passover celebrated in exile, and that next year, we may merit to celebrate it in Israel. This expresses the longing of Jews living outside of Israel in centuries of exile to go home to their homeland, Israel, and a belief that the Third Temple will be built, triggering a mass ingathering of those exiled.