The wicked one, what does he say? “What is this service to you?!” He says `to you,’ but not to him! By excluding himself from the community he has denied the most fundamental fact. You, therefore, blunt his teeth and say to him: “It is because of this that HASHEM did for me when I left Egypt”; `for me’ – but not for him! If he had been there, he would not have been redeemed!”
Because of this: In order that I fulfill His commandments, such as these; the Passover sacrifice, Matzah, and bitter herbs. (Rashi)
HASHEM did for me: alludes to a reply to the wicked son, to say, “HASHEM did for me,” but not for you. Had you been there, you would not have been worthy of being redeemed. (Rashi)
This is the answer prescribed for the wicked son and his cynical attitude at the Pesach Seder. We tell him “because of this HASHEM did for when I went out of Egypt.” Here we sit thousands of years after the Exodus, talking to a non-compliant child and asking him to understand somehow that “I went out of Egypt”! How is he supposed to hear this as a relevant and credible response to his already deep skepticism?
What is “this” referring to as in “because of this”? “This” is usually pointing to something tangible and concrete before our eyes in the present. Rashi comes galloping to the rescue and answers the question about “this”. It is talking about the Mitzvos of the evening that we are fulfilling at the Seder such as Matzah, Marror, and the Pesach Offering.
Great! How is that an answer to the wicked son? Even if he’s convinced that HASHEM took us out of Egypt, it’s been a long time since that event!
Again Rashi provides the information for the answer, breathing life into the dialogue. The wicked son is being told that had he been there in Egypt he would not have been one of the redeemed. Harsh words! Therefore HASHEM did for me and not him! How does that answer his question?
Imagine a farmer planting the seed to an apple tree. Maybe he hopes that at a time in the near future he will witness the literal fruits of his labor as a tree filled with apples unfolds before his eyes. If he is a far thinking farmer he may also have in mind the many generations of trees, and a whole orchard of apple trees that will result from a single excellent seed. It has been said, “Any fool can tell you how seeds are in an apple but only HASHEM can tell you how many apples are in are in a seed.”
When we are seated around the Pesach Seder, we are obligated to understand that the Exodus from Egypt was because of me. “Because of this HASHEM did all this for me…” HASHEM had me in mind at that time that I would be seated here in the 21st century munching Matzos. It’s not that HASHEM took out the Jewish People 3329 years ago and as a result here we are. No! HASHEM had in mind then anyone who is here now happily fulfilling Mitzvos. I can in fact now choose to be chosen. That’s the Pesach opportunity!
The wicked son is being admonished his contrarian attitude. By foolishly deciding that it’s not worth being here and now, he has tragically removed himself from the list of those HASHEM had in mind back then. There’s a Gemora concept called “Yeish Breira”, that a decision made now effects reality retroactively. The Pesach Seder is actually a journey back to the future where we discover that these really are the good old days.