Yahweh speaks of all of the Israelites who are in exile as if they are one person, with one heart and one spirit. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here the metonym "heart" represents the will and emotions. Yahweh speaks of causing all of the people to share the same new emotions as if he were giving them one heart. (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-metaphor]])
Here the metonym "spirit" represents the thoughts and disposition. Yahweh speaks of causing the people to think new thoughts as if he were giving them a new spirit. (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-metaphor]])
Yahweh speaks of the people being stubborn as if they had a stone heart and of their being willingly obedient as if they had a heart of flesh. He speaks of causing them to become willingly obedient as if he were exchanging those two hearts. Alternate translation: "I will cause them to stop being stubborn and instead cause them to obey me willingly" (See: [[rc://en/ta/man/jit/figs-metaphor]])