מוסר אויף בראשית 3:7

The Sages have said: "Intelligence is a sense of shame and a sense of shame is intelligence." For regarding Adam and Eve, it is said: "The two of them were naked and yet they felt no shame" (Gen. 2:25). And they did not understand what modesty is and they could not distinguish between good and evil. But, after they had eaten of the Tree of Knowledge, it is said: "Then the eyes of both of them were opened" (Gen. 3:7).

The reason that these numbers need to be found in the construction of the תפילין is the statement of the Talmud Kidushin 35, based on: למען תהיה תורת השם בפיך that the entire Torah is compared to תפילין (Exodus 13,9).

Nachmanides, in his book Igeret Hakodesh, has already written about the significance of the terms ידיעה and חיבור when used to describe sexual unions. Before man sinned and became polluted with the זוהמה, the filth of the evil urge, the act of copulation was considered the fulfillment of a מצוה, similar to all other מצות. Just as one employs one's hands to fulfill the commandment of building a סוכה, hut, or one takes a לולב, palm frond, in one's hands, so one uses a different organ to fulfil the commandment of being fruitful. The genitals were created to enable man to perform this commandment, and there was no feeling of shame or embarrassment attached to the act Only after the serpent had made man aware that he was nude, and that the very condition of nudity was something to be embarrassed about, did the act of sexual union become associated with feelings of shame and embarrassment. In the future, when G–d will remove the evil urge from us, and we shall again be as free from sin as Adam was before his sin, the act of physical union between man and wife will again be the performance of a מצוה like all other מצות.