לֹא־תֹאכַ֤ל עָלָיו֙ חָמֵ֔ץ שִׁבְעַ֥ת יָמִ֛ים תֹּֽאכַל־עָלָ֥יו מַצּ֖וֹת לֶ֣חֶם עֹ֑נִי כִּ֣י בְחִפָּז֗וֹן יָצָ֙אתָ֙ מֵאֶ֣רֶץ מִצְרַ֔יִם לְמַ֣עַן תִּזְכֹּר֔ אֶת־י֤וֹם צֵֽאתְךָ֙ מֵאֶ֣רֶץ מִצְרַ֔יִם כֹּ֖ל יְמֵ֥י חַיֶּֽיךָ׃
Non mangerai pane lievitato con esso; per sette giorni mangerai pane azzimo, anche il pane dell'afflizione; poiché sei uscito in fretta dal paese d'Egitto; che tu possa ricordare il giorno in cui sei uscito dalla terra d'Egitto per tutti i giorni della tua vita.
Rashi on Deuteronomy
לחם עני THE BREAD OF AFFLICTION — i.e. bread that calls to mind the affliction to which they were subjected in Egypt (Sifrei Devarim 130:5).
Sforno on Deuteronomy
לא תאכל עליו חמץ שבעת ימים, even though in Egypt the prohibition of eating chametz was in effect for only one day, as our sages pointed out in Pessachim 96.
Rabbeinu Bahya
לא תאכל עליו חמץ, “Do not eat any leavened matter with it.” This refers already to the time when the Passover sacrifice may be slaughtered, i.e. about midday. At that time one must no longer own anything leavened (Ibn Ezra).