Ketubot, Chapter One, Mishnah Four
This mishnah teaches the opposite cases of those taught in mishnah two.
1) A virgin, who was a widow, a divorcee, or a halutzah from marriage her kethubah is a maneh, and there is no claim of non-virginity upon her.
2) A female proselyte, a woman captive and a woman slave, who have been redeemed, converted, or freed [when they were] more than three years and one day old their kethubah is a maneh, and there is no claim of non-virginity upon her.
Section one: The women in this mishnah have been previously married, and not merely betrothed as were the women in mishnah two. Nevertheless, they are still virgins for their husbands divorced them or died after entering the huppah (the wedding room) before having had sexual intercourse. Note that this could certainly occur if the woman was menstruating at the time of marriage. The mishnah rules that although these women are physically virgins, they are halakhically considered to be non-virgins and are treated as such. Their ketubah payment in a subsequent marriage will therefore be only a maneh and not the full 200 zuz. If their husband in a subsequent marriage marries them and finds them not to be a virgin, he cannot make a virginity claim against them. One reason that they are considered to be non-virgins is that by definition a woman who was once married can no longer be a virgin, for the word for virgin in Hebrew implies unmarried. A second reason is that although the woman claims to be a virgin, since she was married, we cannot assume that she is telling the truth.
Section two: The women in this mishnah converted, were freed from slavery or were freed from captivity after the age of three years and one day. Since it is assumed that in their previous state they had sexual intercourse they cannot claim to be virgins when they grow up and get married. This is because if a girl has sexual intercourse past the age of three years her physical signs of virginity will not return (see the commentary on mishnah two).