וְהִגַּדְתָּ֣ לְבִנְךָ֔ בַּיּ֥וֹם הַה֖וּא לֵאמֹ֑ר בַּעֲב֣וּר זֶ֗ה עָשָׂ֤ה יְהוָה֙ לִ֔י בְּצֵאתִ֖י מִמִּצְרָֽיִם׃
너는 그 날에 네 아들에게 뵈어 이르기를 이 예식은 내가 애굽에서 나올 때에 여호와께서 나를 위하여 행하신 일을 인함이라 하고
Tiferet Shlomo
"You pour the cup and hear the son asks what..." (Hagadah): This hints to the fact that the night is called the Second Level of Greatness [a kabbalisitic concept], and this is the level of the question of the father to the son (and then it returns because Hashem's kindness is everlasting).