Evil will be rectified

Yaakov and Esav were twins because also Evil will be rectified as the sages state: "the head of Esav rests in the lap of Yitzchok" which is the secret of Evil returning to the good, the secret that in the future the pig will become pure and the Holy One will slaughter the Angel of Death, namely "death will be swallowed forever" and it will remain an "Angel". Because the head of klipa has an attachment to kedusha like the head of Esav in the lap of Yitzchok, but when it extends from there it becomes tuma...Regarding סמא-ל Sama'el, the Sar of Esav, the סם "Sam" [poison] will be erased and the א-ל "Kel" [Divine name] will remain.

Shelah Hakadosh, parshas Chayei Sarah

Tzaddikim Do Not Die: They Transform the Physical into Spiritual

"And Sara died" (Chayei Sara 23:2)

The verse hints at what it says "Kiryas Arba" ("City of the Four"), to say that G-d-forbid one should not connect death with tzaddikim. Rather, Kiryas Arba means the city that was built from the four yesodos (fundemental elements) became separated and departed from them. And in saying "this is Chevron" implies that even though she died, she caused them [the four yesodos] to have the aspect of unification (chibur) because tzaddikim, even though they will die yet the body is not negated from life because tzaddikim in their deaths are called living. Go and learn from what occurred with Rav Achai bar Yoshiya (Shabbos 152).

The reason is because when they are in the world they transform the aspect of holy spirituality that is in their nefesh via their good deeds and abundant Torah that they accomplish in this world. Go and learn from the Rambam (Hilchos Yesodei Hatorah perek daled) that it is a rule of Hashem that one yesod can transform into its neighboring yesod: earth transforming into water, and similarly we find that via the clinging of a person to his Creator he can transform all the yesodos to [the highest] yesod of fire, and from the [material] yesod of fire to the yesod of fire of the neshoma. (Ohr Hachayim on the posuk)

Four Fundemental Elements United

"And Sara died in Kiryas Arba, this is Chevron, in the land of Canaan." (Bereishis 23:2)

Rabbi Yitzchok said in the name of Rabbi Yochanon: the Holy One created man and put into him four things that are divided in the body. Rabbi Yehuda said [things that are] unified in the body. Rabbi Yitzchok said they are divided in the body because they divide up each to its own fundemental element when the person departs from this world. Rabbi Yehuda said they are unified in the body during his life.

Learn from the verse that states "and Sarah died", this refers to the body; "in Kiryas Arba", these are the four fundemental elements; "this is Chevron" means they were unified in his body in his life; "in the land of Canaan" means in this world.

Zohar, Chayei Sara 122b