Will they receive a new heart?
Rashi: The Yetzer ha'Ra will be made for good.
Radak: They will have a heart that hears.
Radak citing Targum Yonasan: A heart that fears.
Malbim: Until now, the reasons for sin were the heart and Ru'ach. The heart is the ruling power that leans towards desire, and the Ru'ach puts evil images on the heart. I will give to you a new heart that leans only towards good. The Ru'ach will put only good images on the heart.
What "Ru'ach Chadashah" will they receive?
Radak: It is a proper Ru'ach, to accept Hashem's words with love.
Radak citing Targum Yonasan: A Ru'ach that fears.
Malbim: Refer to 36:26:1:4.
What is "Lev ha'Even"?
Radak citing Targum Yonasan: The heart of Resha'im, which is hard like stone.
Malbim: The heart is hard, and does not accept Musar and rebuke, just like it is hard to engrave in a rock.
What is "Lev Basar"?
Radak: A soft heart; it is proper to receive good.
Radak citing Targum Yonasan: A heart that fears Me, to do My will.
Malbim: It is a heart that easily accepts good images of Yir'as Hashem and love of Him.
