“When a woman conceives and gives birth to a boy, she shall be ritually unclean for seven days, just as she is unclean during the time of separation when she has her period.”
Adam was created from the earth outside of the Garden of Eden, and later God brought him in. Why is this so? Would it not be better to create Adam from the earth of the Garden, which was obviously of better quality? However, the reason for this is that Adam was destined to make a mistake that would cause him to be exiled from the Garden. Had Adam been created from the earth of the Garden of Eden, then later, after his mistake and exile, he would not be able to repair the damage he has done.
When the Snake seduced Eve, he injected in her bad spiritual qualities that led to a mixture of good and evil. Now she would give birth not only to righteous individuals, like she and Adam, but also to evil people. There are connections between the seventy nations of the world, the seventy members of Sanhedrin, the seventy years of exile, the seventy years of the “spiritual sleep” of the exiles, and seventy or eighty years of a man's life, hinted to in the psalms, “the life of a man is seventy years, and with strength – eighty.” They deal with the mixture of good and bad, and that explains why circumcision happens on the eight day, which is free from the influence of seven/seventy.
Art: Francesco Curradi - The Expulsion of Adam and Eve from Paradise