I’m going to take the easy way out today and take most of what I’m going to say from Rabbi Shulman’s last Shabbat Hagadol Drash. The parasha describes how Pesach is to be observed in future years:
It all sounds very nice, but חז״ל saw in the children’s comment a negative side:
There is more to say about the Four Sons than can ever be said, but there are a few questions that I would like to address: First, why do we interpret the “wicked” son’s answer as “wicked”? Second, what does הַקְהֵה אֶת שִנָּיו means? Third, why does the בעל ההגדה supply a different answer from the one given in the text; why does he recycle the answer given for the שֶׁאֵינוֹ יוֹדֵעַ לִשְׁאוֹל?
Let’s look at the other sons in the text:
The רָשָׁע's answer certainly seems sarcastic, as opposed to the more nuanced מה העדת והחקים והמשפטים of the חָכָם. More than that, we can see subtle differences in how the Torah presents the רָשָׁע compared to the other two sons who ask questions. First, the רָשָׁע doesn’t ask. The other two use the verb ישאלך; the רָשָׁע uses יאמרו. He isn’t really asking; he’s trying to make a point. The other two ask מחר; the רָשָׁע doesn’t. The implication (that I cannot remember where I read) is that the other two have the attitude of נעשה ונשמע, of being willing to serve even without understanding the reason why. The כלי יקר points out that the רָשָׁע is asking in the plural:
So we can see the רָשָׁע's comments as negative. But our response is not to exclude him:
What does הַקְהֵה אֶת שִנָּיו mean? It is often translated as “blunt”, as in (קוהלת י:י) אם קהה הברזל, ”if the axe is blunted“; as though to say you should reduce the impact of his “biting” remarks. And that is the modern Hebrew meaning. But that is not how הקהת שינים is used in תנ״ך:
Thus תקהינה שניו has the sense that the the guilty would feel the effects of their actions. In the הגדה, it is a matter of turning the רשע's words on himself. The response of לי ולא לו is not inherent in our answer:
The halacha of והגדת לבנך ביום ההוא לאמר: בעבור זה עשה ה׳ לי בצאתי ממצרים applies to all children, no matter what their attitude. We tell all our children the story of the Exodus with בעבור זה עשה ה׳ לי בצאתי ממצרים; the שֶׁאֵינוֹ יוֹדֵעַ לִשְׁאוֹל simply has no other questions, so that is all we need to say. To the רשע, we give this answer as well. If he wishes to exclude himself from עשה ה׳ לי, we can tell him אִילּוּ הָיָה שָׁם, לֹא הָיָה נִגְאָל. But what of the answer that the Torah supplies? The כלי יקר gives a number of explanations, but prefers:
It our statement to ourselves, to reinforce our conviction in the face of the mocking of the רשע. It is in fact a separate mitzvah:
There’s an interesting twist on this from the ירושלמי, where רבי חייא (second century CE) brings his own version of the רשע:
רבי חייא lived at a time when Christianity was gaining popularity and his comment to the רשע treats him as an adherent of the new religion, which declared that the “ceremonial law” of the Torah was superseded by the new revelation. There’s a hint in our version as well; the phrase תקהינה שניו appears right before ירמיהו's prophecy of הנה ימים באים נאם ה׳; וכרתי את בית ישראל ואת בית יהודה ברית חדשה. But the real ברית חדשה comes with נתתי את תורתי בקרבם; one cannot separate the “moral law” from the “ceremonial law”. All of בני ישראל have to participate together in the קרבן פסח; to exclude oneself from that is to be כּוֹפֵר בְּעִקָּר.