Rabban Gamliel was accustomed to say, Anyone who has not said these three things on Pesach has not fulfilled his obligation, and these are them: the Pesach sacrifice, matsa and marror.

The Pesach [passover] sacrifice that our ancestors were accustomed to eating when the Temple existed, for the sake of what [was it]? For the sake [to commemorate] that the Holy One, blessed be He, passed over the homes of our ancestors in Egypt, as it is stated (Exodus 12:27); "And you shall say: 'It is the passover sacrifice to the Lord, for that He passed over the homes of the Children of Israel in Egypt, when He smote the Egyptians, and our homes he saved.’ And the people bowed the head and bowed."

He holds the matsa in his hand and shows it to the others there.

This matsa that we are eating, for the sake of what [is it]? For the sake [to commemorate] that our ancestors' dough was not yet able to rise, before the King of the kings of kings, the Holy One, blessed be He, revealed [Himself] to them and redeemed them, as it is stated (Exodus 12:39); "And they baked the dough which they brought out of Egypt into matsa cakes, since it did not rise; because they were expelled from Egypt, and could not tarry, neither had they made for themselves provisions."

He holds the marror in his hand and shows it to the others there.

This marror [bitter greens] that we are eating, for the sake of what [is it]? For the sake [to commemorate] that the Egyptians embittered the lives of our ancestors in Egypt, as it is stated (Exodus 1:14); "And they made their lives bitter with hard service, in mortar and in brick, and in all manner of service in the field; in all their service, wherein they made them serve with rigor."

In each and every generation, a person is obligated to see himself as if he left Egypt, as it is stated (Exodus 13:8); "For the sake of this, did the Lord do [this] for me in my going out of Egypt." Not only our ancestors did the Holy One, blessed be He, redeem, but rather also us [together] with them did he redeem, as it is stated (Deuteronomy 6:23); "And He took us out from there, in order to bring us in, to give us the land which He swore unto our fathers."

It is a mitzvah to distribute to the children toasted grains and nuts so that they will see a change and they will ask.

"They will ask" -- rather, by means of this it will stir within them to pay attention over all of the changes customs of the night, and they will ask pointed questions about the liturgy "what has changed?"

(23) Lo, I will send the prophet Elijah to you before the coming of the awesome, fearful day of YHVH. (24) He shall reconcile parents with children and children with their parents, so that, when I come, I do not strike the whole land with utter destruction.