Yevamot, Chapter Ten, Mishnah Eight
This mishnah continues to discuss the ramifications of an act of intercourse performed by a boy of the age of nine years and one day.
1) If a boy of the age of nine years and one day had intercourse with his yevamah and afterwards had intercourse with her rival wife, he has disqualified [both women for marriage] with himself.
a) Rabbi Shimon says: he does not disqualify them.
2) If a boy of the age of nine years and one day had intercourse with his yevamah and then died, she must undergo halitzah but may not be taken in yibbum.
3) If he had married [any other] woman and she subsequently died, she is exempt [from both halitzah and yibbum].
Section one: As we learned in yesterdays mishnah, according to the rabbis an act of intercourse done by a boy nine years and one day old partially acquires a yevamah as a wife. It is akin to maamar, which also partially acquires the yevamah as a wife. Therefore, if the boy has intercourse first with one yevamah, and then with another one, who is also a yevamah, it is like giving maamar to two different Yevamot. In such a case, he may not marry either one.
Rabbi Shimon holds that it is doubtful whether the sexual act of a boy nine years and one day old acquires a wife. Therefore, if it does make her his wife, then the first yevamah is his wife, and the intercourse with the second woman is inconsequential. If such an act does not acquire her as a wife, then neither did the intercourse with the second woman, and neither are prohibited to him. Therefore, according to Rabbi Shimon, when he reaches majority age he may marry either woman.
Section two: As stated above, intercourse with a boy nine years and one day old is legally equivalent to maamar. It therefore creates a tie to the yevamah, but does not totally remove the ties that she still has to her first husband. Should this boy now die, she has ties to two yevamim (two brothers, both of whom were her husband). As we learned in mishnah 3:9, when a woman has ties to two yevamim she must undergo halitzah, and may not have yibbum with another brother.
Section three: If a boy three years and one day old tries to marry a woman, and then he dies, she is not liable for yibbum or halitzah. This is because a boy this young cannot legally contract marriage. Throughout this chapter we have learned that there are some legal ramifications to his having sex with a woman. This section teaches that those ramifications are limited to the realm of yibbum. For regular marriage, there are no ramifications.