וְזָ֣כַרְתָּ֔ כִּי־עֶ֥בֶד הָיִ֖יתָ בְּאֶ֣רֶץ מִצְרָ֑יִם עַל־כֵּ֞ן אָנֹכִ֤י מְצַוְּךָ֙ לַעֲשׂ֔וֹת אֶת־הַדָּבָ֖ר הַזֶּֽה׃ (ס)
Et tu te souviendras que tu as été esclave au pays d’Égypte: c’est pourquoi je t’ordonne de tenir cette conduite.
Ibn Ezra
The concept of remember that you were a slave is associated with the concept of being an “alien” [: 21].
Sforno
וזכרת כי עבד היית, and at that time you were in need of even unripe grapes.