Musar su Amos 7:2

Sanctification of the body, i.e. refining the body is a preliminary for attaining sanctity of the spirit, for coming close to G–d. This is achieved through separating oneself from physically pleasurable experiences even when these are permissible, as we know from the statement of our sages קדש עצמך במותר לך, "if you wish to sanctify yourself do it by refraining from that which is permissible" (Yevamot 20). There are different kinds of "holiness;" all of them refine the body, prevent it from being something gross, and enable the person who is so sanctified to achieve mastery of mind over matter. When carried to the maximum extent possible, the body becomes an insignificant part of the total personality. When the Torah (Deut. 7,7) describes the reason G–d liked the Jewish people as כי אתם המעט מכל העמים "For you are the smallest of all the nations," the word המעט refers to the relative insignificance of the body of the Jew when compared to his mind, his soul. This is also the reason Amos 7,2 describes Jacob as קטן, small. Compared to Esau the part the body plays in Jacob's total personality is insignificant, small. When Esau first emerged from his mother's womb, his body was full of the pollutants of the original serpent. By that time this pollutant had left the body of Rebeccah and Jacob emerged; he was predominantly spiritual and only marginally tainted with the remaining pollutant. The impurity of the menstruating woman is none other than the residual pollutant first absorbed by Eve when the serpent mated with her. Esau's being אדמוני, reddish looking, is a reflection of the quantity of the blood of menstruation. The liver is all blood. Pursuing one's physical desires, giving in to the "fire" of one's passions originates in the liver. "Fire" is synonymous with destruction. The reason such an unrefined person cannot come close to G–d is that the state of his body makes his contact with fire an experience that consumes him rather than one which "warms" him.