en_tn/rom/10/10.md

For with the heart one believes unto righteousness, and with the mouth one confesses and is saved

Here "heart" is a metonym that represents the mind or will. Alternate translation: "For it is with the mind that a person trusts and is right before God, and it is with the mouth that a person confesses and God saves him" (See: rc://en/ta/man/translate/figs-metonymy)

with the mouth

Here "mouth" is a synecdoche that represents a person's capacity to speak. (See: rc://en/ta/man/translate/figs-synecdoche)