Encamped at Gilgal, in the steppes of Jericho, the Israelites offered the Passover sacrifice on the fourteenth day of the month, toward evening. On the day after the Passover offering, on that very day, they ate of the produce of the country, unleavened bread and parched grain. On the same day, when they ate of the produce of the land, the manna ceased. The Israelites got no more manna; that year they ate of the yield of the land of Canaan. -Joshua 5:10-12
We learn in chapter 5 of Joshua that while the generation of the Exodus had been circumcised in Egypt, their children and grandchildren born in the desert had not been. And since only the circumcised may eat of the Passover sacrifice, it seems that this ritual too was not maintained during the forty years in the desert. Anyway, we couldn't have eaten matzah in the desert as we had no grain only manna. Thus, the first Passover in the land of Israel was rather a significant event, a new experience for the people.
And when you enter the land that the Lord will give you, as He has promised, you shall observe this rite. And when your children ask you, "What do you mean by this rite?" You shall say, "It is the Passover sacrifice to the Lord, because He passed over the houses of the Israelites in Egypt when He smote the Egyptians, but saved our houses." -Exodus 12:25-27
It is interesting to try to imagine the questions that were asked at that first seder in the land
On all the other nights of all the years of our lives we ate manna, which had the quality of tasting like whatever we wanted it to taste like (e.g., lobster); why tonight do we eat only this dry matzah?
On all other nights we ate food that fell from heaven all we had to do was gather it; why tonight do we only eat bread that is the product of our labors of cultivation and preparation?
On all other nights we sat on our suitcases; why tonight have we unpacked?
On all other nights we drank water from Miriam's miraculous portable well; how on this night will we stay awake if all we have to drink is the wine of the grapes of the Land of Israel?
On all other nights we were surrounded and protected by the endless desert; why tonight do we sit with our doors open to listen for any suspicious activity by our new neighbors?
On all other nights we were all equal, sustained by God's providence; why tonight are there poor among us for whom we must we take responsibility?
On all other nights we knew we could rely on Moses to lead us; why tonight is our dinner-table conversation about the crisis of leadership?
On all other nights we looked out of our tents at an endless and unknown wilderness; why tonight does every hill and valley, every rock and tree suddenly have a name and a meaning for us?
On all other nights, when we felt that we belonged someplace it was Egypt; why tonight do we feel we belong here?
On all other nights we could ask our parents about their memories of slavery and redemption; how on this night shall we answer our children's questions?
On all other nights we worried about getting to the Land of Israel; why tonight do we worry about being allowed to stay here?
On all other nights, we studied the Torah as a theoretical exercise, relevant to some distant future; why tonight does the transition from theory to practice seem so overwhelming?
On all other nights, it was the older generation who were responsible for our predicament; why on this night are we suddenly responsible for ourselves?
On all other nights, we dreamed of coming into our own land, that had been promised to us; of what shall we dream tonight?