an upright heart

"a sincere heart." A person who is sincere will do what is right. The heart refers to the center of emotions in a person. See how you translated "uprightness" in Psalms 25:21. (See: rc://en/ta/man/translate/figs-idiom and rc://en/ta/man/translate/figs-metonymy)

your statutes

"Statutes" refers to God's laws or commands.