en_tn/deu/09/05.md

General Information:

Moses continues to speak to the Israelites as if they are one person. (See: rc://en/ta/man/jit/figs-you)

the uprightness of your heart

This is an idiom. "because you always thought and desired the right things" (See: rc://en/ta/man/jit/figs-idiom)

so that he may make come true the word

Here the metonym "the word" refers to what God has promised. Alternate translation: "so that he may fulfill the promise" (See: rc://en/ta/man/jit/figs-metonymy)

your ancestors, to Abraham, Isaac, and Jacob

Abraham, Isaac, and Jacob are the "ancestors" of whom Moses is speaking.