Ketubot, Chapter One, Mishnah Two
This mishnah begins to discuss the size of a womans ketubah. To remind ourselves, the ketubah referred to in this mishnah is the minimum payment that a husband must pay his wife upon his death or divorce. The function of the ketubah was twofold: to provide financial protection for a woman if she was divorced or widowed and to create a financial deterrent for divorce. In other words the husband would not want to divorce his wife because it would cost him too much money (I believe this deterrent is often still effective today.)
1) A virgin her kethubah is two hundred [zuz], and a widow a maneh (100 zuz).
2) A virgin, who is a widow, [or] divorced, or a halutzah from betrothal her kethubah is two hundred [zuz], and there is upon her a claim of non-virginity.
3) A female proselyte, a woman captive, and a woman slave, who have been redeemed, converted, or freed [when they were] less than three years and one day old their kethubah is two hundred [zuz] there is upon them a claim of non-virginity.
Section one: This section provides the basic halakhah that will be discussed throughout the remainder of the chapter. Assumedly there are two reasons why a widow (which in this context includes a divorcee) receives a smaller ketubah. First of all, she already received a ketubah from her first marriage, and therefore has some money already saved up. Second, and probably more importantly, there was a need to encourage men to marry widows and divorcees. Most men probably preferred first-time marriages. Second marriages were made cheaper, therefore, to prevent older women from remaining husband-less. Needless to say, that people should be married was an important value to the rabbis.
Section two: The Mishnah now begins to discuss exceptional cases, ones which slightly deviate from the typical first marriage or the typical widow or divorcee. If a woman has been betrothed, but then was divorced before marriage or her husband died before the marriage was completed is in one sense a virgin and in one sense not. She is a virgin in that she has never had sexual relations, but she is a widow or divorcee as well. [Note that in Hebrew the word for virgin betulah can mean either a woman whose physical signs of virginity are intact or it can mean a young woman who has never been married. The same ambiguity occurs in the Greek word, parthenon.] According to our mishnah, such a woman receives a full ketubah, should she remarry.
Section three: In order to understand this section we must understand a few things. First of all, all of the women mentioned in this mishnah are assumed to have already had sex. It was assumed that female captives were raped by their captors and therefore a woman who had been taken captive was assumed to no longer be a virgin. It was also assumed that non-Jews were extremely licentious, and that they would have sex with young girls (I realize that this is extremely bigoted, but there probably was some degree of truth to it in the world in which the rabbis lived). Therefore a woman who converted was assumed to have already had sex. Thirdly, it was assumed that slaves were licentious or perhaps were commonly raped by their masters. In any case, they too were categorically not considered virgins. Seemingly all three of these types of women should have Ketubot of one maneh [=100 zuz] and their husbands should not be able to claim that they werent virgins, because they were married under the assumption that they were not virgins. However, the other assumption that the mishnah makes is that if a girl is raped before the age of three, her signs of virginity will eventually heal and return [this medical assumption was not unique to the rabbis]. Therefore if these women made the transition from slave to free Jew or proselyte to Jew or from captive to being freed before the age of three, it was assumed that their virginity would return and they could be assumed to be virgins.
A note about the Mishnahs references to sexual intercourse with young girls:
The Mishnah will occasionally reference sexual relations with young girls, even under the age of three. I expect that this will cause discomfort to people reading the mishnah, and when I think of my own three year old daughter, this makes me queasy as well. We would do well to realize that the Mishnahs discussion of all legal possibilities does not imply their tacit approval of them. The Mishnah discusses many crimes without expressing horror over them, because the Mishnah is often interested in legal consequences. The rabbis certainly did not condone sexual relations with girls this young.