Musar su Levitico 18:7

Commandments 190, 191 and 192 prohibit sexual relations with one's father, i.e. not to sleep with him as one sleeps with a woman. The operative verse is ערות אביך לא תגלה (18,7). A son must not have sexual relations with his mother; the Torah says: אמך היא לא תגלה ערותה (ibid.) One must not have sexual relations with one's father's wife, even if she is not one's mother; the operative verse is: ערות אשת אביך לא תגלה (18,8)

These commentators describe intercourse with one's mother as disturbing the equilibrium in the domain of the emanation בינה, also known as אם הבנים. It also disturbs the equilibrium of the שכינה, also known as the אם כל חי. This is the reason that the Torah in 18,7 writes ערות אמך לא תגלה אמך היא twice in succession. The only one who is entitled to exert his influence, [masculinity] on the domain of the emanation בינה is the King of Kings. Anyone who usurps this privilege [vicariously of course, Ed.] is guilty of the death penalty. Intercourse with the wife of one's father results in upsetting the domain of the emanation הוד, the natural partner of the emanation נצח. This emanation is also called אב לצדיק. If someone engages in sexual intercourse with his sister he damages the equilibrium of כנסת ישראל, the spiritual counterpart of the Jewish people on earth, the latter being referred to in Song of Songs 5,1 in the words: באתי לגני אחותי כלה.