From the hagada:
חָכָם מָה הוּא אוֹמֵר מָה הָעֵדֹת וְהַחֻקִּים וְהַמִּשְׁפָּטִים אֲשֶׁר צִוָּה ה׳ א׳ אֶתְכֶם.
וְאַף אַתָּה אֱמָר לוֹ כְּהִלְכוֹת הַפֶּסַח אֵין מַפְטִירִין אַחַר הַפֶּסַח אֲפִיקוֹמָן.The wise one, what does he say? "What are the testaments and decrees and rules that God, our god, has commanded you?"
And also you tell tell him like the Pesach rules: we do not tack on dessert after the Pesach.
Why "כְּהִלְכוֹת הַפֶּסַח", "like the Pesach rules"? Aren't we telling him the Pesach rules?