What is the meaning of "Chayei Vesarim Lev Marpei"?
Rashi: A heart of flesh that heals the evil and overcomes his Midos, this is the life of Hashem's creations, who are flesh and blood.
R. Yonah #1: Most cures help some limbs and harm others. A heart of patience is life for all the limbs, Besarim are limbs. A patient heart is called Lev Marpei, for it heals his body and Nefesh from anger and sadness - "v'Haser Ka'as mi'Libecha v'Ha'aver Ra'ah mi'Besarecha" (Koheles 11:10). It heals others via a soft answer - "Ma'aneh Rach Tashiv Chemah", "u'Leshon Chachamim Marpei" (15:1, 12:18).
R. Yonah #2: Lev Marpei is a good heart - he seeks good for his nation (Esther 10:3). It is Chayei Vesarim, for hatred and envy will not take effect in them.
What is the consequence of "u'Rkav Atzamos Kin'ah"?
Shabbos 152b: Bones rot [even after death] only if the person was jealous.
Rashi: An angry person is corrosion of bones to everyone.
R. Yonah: It goes without saying that envy thins the flesh. Even bones, which are hard, they rot due to the illness of envy. Envy is the opposite of Lev Marpei - the latter is life of the limbs, and envy makes the bones rot! Alternatively, it is because the result of envy is from the place of the result of anger - from black bile.
Malbim: Refer to 14:29:3:3.