Introduction This mishnah teaches that in a legal sense, sexual relations with a girl over the age of three counts as sexual relations. I should emphasize that this mishnah in no way condones such an act (which is certainly rape) it just teaches that this counts as an act of intercourse. At the core of this notion is their understanding of the physical consequences of intercourse for the first time namely the breaking of the woman's hymen. As we can see at the end of the mishnah, if a girl has intercourse (i.e. is raped) before the age of three her hymen will repair itself. After the age of three, it will not. This, to the rabbis, means that after the age of three, intercourse "counts" in a legal sense. Before the age of three, it does not. Having taught this mishnah (and others like it) many times, I realize that this is a very sensitive issue. To talk about sex with young girls is very troubling. I certainly don't want people to read this and think that the rabbis thought that it was okay for men to have relations with little girls. As usual, the mishnah uses a clinical, emotionally distant tone. That's just the way the rabbis composed much of the mishnah.
A girl of the age of three years and one day may be betrothed by intercourse and if a yavam had intercourse with her, he acquires her thereby. As stated above, intercourse with a girl over the age of three years counts as intercourse. Therefore, since betrothal may be performed by intercourse, she may also be betrothed in this way. If she is liable for yibbum (meaning her previous husband died without any offspring) and the yavam (her dead husband's brother) had intercourse with her, she becomes his wife. Again, this means that intercourse with her creates legal obligations and a legal relationship.
One can be liable for adultery with her; If her father marries her off to someone (this can be done even before three years old) and then another man has intercourse with her, he is liable for adultery and he would get the death penalty.
And she defiles the one who had intercourse with her so that he in turn conveys uncleanness to a couch underneath as to a cover above. If she is a niddah, she defiles one who has intercourse with her such that he would defile any number of couches or cushions upon which he sat. This was explained in 4:1.
If she was married to a priest, she may eat terumah. An Israelite woman married to a priest can eat terumah. Since this marriage counts, she can eat terumah.
If any of the disqualified men have relations with her he disqualifies her from the priesthood. If someone who is disqualified from the priesthood, such as a halal (a disqualified priest) or a non-Jew, has relations with her, he disqualifies her from subsequently marrying a priest. This is true of all women.
If any of the forbidden relatives found in the Torah had relations with her he is to be executed on her account, but she is exempt [from the penalty]. If a man forbidden to her because of incest has relations with her, he gets the death penalty (as long as the incest was punishable by death). She, of course, is not punished because little children cannot be held accountable for their actions. Obviously, this was an act of rape.
If she was younger than this age, intercourse with her is like putting a finger in the eye. This is the concept I mentioned in the introduction. If one pokes someone in the eye, the eye tears up but returns to normal. So too, the rabbis believed that if one had intercourse with a girl younger than three, her hymen would repair itself. She would remain a "virgin" and therefore there are no legal consequences to relations with her.