וְהָיָ֕ה כִּֽי־יֹאמְר֥וּ אֲלֵיכֶ֖ם בְּנֵיכֶ֑ם מָ֛ה הָעֲבֹדָ֥ה הַזֹּ֖את לָכֶֽם׃
Wenn nun eure Söhne euch fragen: Was bedeutet dieser Brauch?
Targum Jonathan on Exodus
And it shall be that when at that time your children shall say to you, What is this your service?