Israel is a tree, and the people are branches.

On Palm Sunday, the people cut branches from trees and wave them before Jesus.  They are cutting themselves from the tree of Israel, and grafting in as branches of the true Israelite tree, the stump of Jesse.

But that tree is going to Jerusalem to be cut down, and when the tree is cut, all the branches are going to be removed and tossed aside.  Only after the resurrection does a new Israel tree grow.