In Isaiah 53, the Suffering Servant is said to be “cut off” from the land of the living (Is. 53:8). This is not just a euphemism for death. To be “cut off” is to suffer the consequences of breaking covenant (Gen. 17:14, Ex. 12:15).
In the Passover text, to refuse to get rid of the leaven of Egypt, is tantamount to refusing to leave Egypt. But if you are an Israelite clinging to Egyptian ways and life, you will be struck by the tenth plague. You will be “cut off.”
For Christ to suffer like “a lamb to the slaughter” (Is. 53:7) and to be “cut off from the land of the living” (Is. 53:8) is to tie both elements of the Passover together. Christ as the Passover lamb dies like an Israelite-Egyptian, an Israelite who has refused to be delivered, refused to be rescued, who prefers slavery in Egypt.
Christ dies under the curse of the covenant, like an Israelite rebel, like an Israelite idolater and slave, so that the covenant breakers might be forgiven, so that the rebels might be reconciled, so that the slaves might go free.