RobH_en_tn/deu/15/15.md

remember that you were a slave

Here "you" includes their ancestors that were slaves for many years. Alternate translation: "remember that your people were once slaves" (See: rc://en/ta/man/translate/figs-you)

that Yahweh your God redeemed you

Yahweh rescuing the people of Israel from being slaves in Egypt is spoken of as if Yahweh paid money to redeem his people from slavery. (See: rc://en/ta/man/translate/figs-metaphor)