As we’ve learned, the purpose of levirate marriage is to produce a child who will carry on the name of a man who died childless. This raises the obvious question of how to deal with a situation in which a potential yavam is infertile.
On yesterday’s daf, we encountered a mishnah dealing with men who lose the ability to father children due to an accident that damages their sexual organs or who are unable to do so from birth. Today’s daf cites a teaching in which the rabbis list the characteristics of a person in the latter category — i.e. one who reached adulthood, but not sexually mature. They include:
The sages taught: Who is considered a eunuch by natural causes? It is anyone who is 20 years old and has not yet grown two pubic hairs. And his signs are as follows: Whoever does not have a beard, and his hair is defective, and his skin is smooth.
Rabban Shimon ben Gamliel says in the name of Rabbi Yehuda ben Ya’ir: It is anyone whose urine does not raise foam.
And some say: It is anyone who urinates without forming an arch.
And some say: It is anyone whose semen dissipates.
And some say: Anyone whose urine does not ferment. Others say: Anyone who bathes in the rainy season and his flesh does not give off steam.
Rabbi Shimon ben Elazar says: It is anyone whose voice is defective, so that it is not evident from it whether he is a man or a woman.
It’s no surprise that the rabbis were aware that the physical characteristics of puberty do not always emerge. As we’ve seen, the Talmud has a sophisticated and nonbinary awareness of sex and gender and acknowledges a variety of pathways for human physical development.
Many of the secondary male sexual characteristics listed here conform to our own understanding of human development. We too understand that the failure of certain characteristics to appear might indicate that a person is infertile. While our understanding may be more grounded in science, we conclude as the rabbis do — some people are unable to have children.
But one item on this list is much harder to reconcile with a contemporary understanding: The person whose flesh does not steam after bathing during the rainy season.
In the rabbi’s day, baths were taken in public bath houses and not in private homes. And during the rainy season — that is, winter — it was probably common for a person to steam as they exited the bath, and the hot water remaining on their body evaporated and then quickly condensed. This explains why a person would steam after bathing during the rainy season. But why would the failure to steam in this matter be an indicator of infertility?
The commentators don’t address this. Nor is it explained in Julius Preus’s Biblical and Talmudic Medicine, the go-to guide for understanding what the rabbis thought about physiology, illness and medicine. My search of the internet did find studies suggesting that hot baths lead to a temporary reduction in sperm count, but it didn’t surface anything that explained why infertile men would not appear to steam when exiting a hot bath.
So we’re left to ponder why the Talmud suggests that some people do not steam upon exiting a bath in the winter. Is that even possible? And even if it were, what would cause the rabbis to think that such people are not sexually mature? As the rabbis themselves might have said — teyku. We just don’t know.
Read all of Yevamot 80 on Sefaria.