Musar su Genesi 49:3

If man and his wife had been able to maintain their state of innocence, the drop of semen from which a fetus develops would not be called a טפה סרוחה, an evil smelling drop. Instead, it would be called זרע קודש, holy seed. The subject of copulation and sex would not then be a subject surrounded by shame and embarrassment. It would be an act of מצוה performance no different from that of putting on phylacteries, and would be performed publicly without shame or embarrassment. An act which is not inspired, at least partially, by the evil urge is not something associated with shame or embarrassment. Now that Adam and Eve had sinned, the act became associated with shame. Jacob, who is described as the "beauty," i.e. the spiritual level of an Adam before sin, began to repair the damage caused through Adam's sin. This is the significance of the oft repeated slogan that "his bed was pure." It means that Jacob only sprouted זרע קודש, "holy seed." Jacob never experienced impurity through the emission of semen for any purpose other than procreation. He was able to say of Reuben his first born, who was conceived when Jacob was at least 84 years old, ראובן בכורי אתה כחי וראשית אוני, "Reuben you are my firstborn, my strength and the first of my vigor" (Genesis 49, 2). Jacob's principal firstborn was Joseph, however, since when he cohabited with Leah, he was under the impression that it was Rachel, the wife he worked for for seven years. This is the reason he could deprive Reuben of his rights as a firstborn and transfer that birthright to Joseph. As a result, it was no more than fair that Joseph's children would receive a double share in the land of Israel, that Menasseh and Ephraim were each considered a tribe. The spiritual identity of Jacob and Joseph is even more evident when we consider Joseph's experience with the wife of Potiphar. Joseph maintained the purity displayed by his father in all matters sexual when he resisted the seduction of Mrs. Potiphar. [He cited as the only reason that it would be a sin against G–d and against her husband. Ed.] It is a well known fact that the צדיק, the righteous individual, is the foundation, יסוד of the world. The emanation ברית העליון, is the source of the תפארת, the covenant emanating in the "highest" regions, a term familiar to students of the Kabbalah. It is a direct continuation of the forces activated in the emanation, תפארת, the emanation which mirrors the attribute of Jacob.

The word אנכי is the mystical dimension of אחד, since when you "square" the letters of the word אחד, the total equals the numerical value of אנכי. The calculation is as follows: you multiply each letter in the word אחד by itself, i.e. 1 by 1=1; +8 by 8=64; +4 by 4=16. This adds up to a total of 81. The word 81=אנכי. The conceptual common denominator between the two words is that just as G–d is unique, i.e. אחד, so Rebeccah as potential founder of the twelve tribes making up the people of Israel is unique. The letters in אחד can also be read as follows: "The nation Israel consisting of 8 tribes born by Jacob's major wives ח, and 4 tribes born by Jacob's minor wives ד, together form one nation, א-אחי. The word אנכי is equivalent to the numerical value of כסא, G–d's throne, where Jacob's likeness is inscribed. After Jacob had received assurances that he would be the founder of twelve tribes, and that these tribes would enjoy G–d's blessings and be the forerunners of the eventual redemption when G–d would be "walking in their midst," he exclaimed that he had absorbed this information and that he had now received the answer to what had troubled his mother when she had questioned the value of her existence, i.e. her אנכי. The Talmud Chulin 91 even describes the ascent and descent of the angels as motivated by their desire to compare the features of Jacob with the image engraved on the throne of G–d. The angels tried to cause Jacob trouble, when G–d intervened. This is the reason why the Torah says: "Here G–d stood on top of him."

Jacob, when he said these words, may possibly have experienced a moment of divine inspiration about the need for the kingdom of Joseph to precede that of Yehudah. What plagued Jacob was 1) that he simultaneously foresaw that the kingdom of David would be split when Jerovam of the tribe of Joseph would command the allegiance of ten of the twelve tribes. At that time Yehudah and Benjamin alone would remain loyal to the house of David. This was one factor which led to the destruction of the first Temple; 2) because Jerovam erected the golden calves which the Ten Tribes worshiped. Later on, Israel committed many other grievous sins. Even the tribes of Yehudah and Benjamin were infected eventually, until this brought about their exile. During the second Temple the Hasmoneans appropriated the "crown" of Royalty which should have been Yehudah's. We have already quoted Nachmanides who explains how the ascent of the slave Herod to the throne in Jerusalem was a punishment for that error of the Hasmoneans, and became the beginning of the end of the second Temple which was eventually destroyed by the Romans.