Musar su Genesi 50:13

Isaac slowed the expansion of the influence of the tree of knowledge by means of the birth of the twins Jacob and Esau. This was an indication that even evil can be rehabilitated. Our sages phrased it thus: Esau's head reposes within the lap of Isaac; such is the mystery of how evil can be rehabilitated. The secret of how this happens was alluded to by our sages' explanation that the reason the pig is called חזיר, (from the root חזר to return) is that in the future it will restore the crown to its Master, as we know from Ovadiah 1,21 ועלו מושיעין בהר ציון … והיתה לה' המלוכה, "For the saviours will march up Mount Zion… and the kingdom will be G–d's." (cf. details in Kohelet Rabbah end section 1). All of these events will occur at the time when G–d will "slaughter" the angel of death. This is the plain meaning of Isaiah 25,8 בלע המות לנצח, "He will destroy death forever." This angel of death will then remain as a regular angel, since all the negative forces we know as קליפות are after all an outgrowth of a holy source. This is what was alluded to in the quote that the head of Esau reposes in Isaac's lap. When the head expands it becomes a symbol of impurity. The very name סמ-אל Samael, (Satan) reflects the dual nature of evil. On the one hand the name א-ל, G–d, is part of that definition, on the other hand the word סם represents the סם המות, lethal poison. In such a future the סם aspect of Satan/ Samael will be abolished. We, the Jewish nation however, are called by the name of G–d. Our sages interpreted Genesis 33,20 ויקרא לו א-ל א-לוהי ישראל, "He (G–d) called him (Jacob) El the G–d of Israel" (Megillah 18a, proving that the word לו could not refer to the altar Jacob had built). We have an allusion to this in Genesis 11,10 אלה תולדת שם, suggesting that we, his descendants, are all a "full name," not half a name such as סמא-ל.