For those who grew up in the United States, the metric system can be confusing. If you’re used to measuring distances in miles and volumes in gallons, kilometers and liters can feel like meaningless terms. In Canada, it’s even worse: Weather is in celsius, body temperature is in fahrenheit and thermostats can go either way. Meanwhile, driving is in kilometers, but height is in feet and inches. It’s enough of a mess that some generous person on the internet created a handy flowchart to help you figure it all out.
Today, our daf introduces us to a measurement unit that’s neither imperial nor metric, but can be equally perplexing: the olive-bulk. The rabbis are in the midst of discussing when and whether impure objects pass along that impurity if we’re not sure whether they came sufficiently close to a person or object. Relying on the Tosefta, the rabbis conclude that, as a rule, impure items being dragged or carried impart impurity if there’s uncertainty on proximity, while objects that are thrown don’t. But there are a few exceptions, including this:
Except for an olive-bulk from a corpse.
That is to say, if a thrown olive-bulk of corpse (now there’s a phrase I never thought I’d write) sails overhead, its impurity is transferred to anyone standing underneath. In the Mishneh Torah, Maimonides breaks this down even further, ruling that an olive-bulk of corpse in the mouth of a raven flying over a group of people renders them impure, but it doesn’t impart impurity to the vessels it flies over. Why the difference? Because the people can answer questions about what exactly happened and where they were standing to help suss the situation out, but vessels can’t.
This isn’t the only place Jewish law hinges on an olive-bulk. Eating an olive-bulk’s worth of bread imposes a duty to recite the Hamotzi blessing and Birkat Hamazon (Grace After Meals). At Passover, a person is obligated to eat an olive-bulk of matzah and an olive-bulk of maror (bitter herbs). Not surprisingly, there’s some controversy about this. Ashkenazi and Sephardic Jews differ over whether an olive-bulk is a unit of volume or mass. There are differing definitions of how much constitutes an olive-bulk, and there’s an argument to be made that the unit’s size has changed over time. So if you’re trying to answer the most obvious question of all — How much is an olive-bulk? — the answer is going to be rather unsatisfying: It depends who you ask.
To make matters worse, the olive-bulk isn’t the only food-related unit of measurement in Jewish law. Maimonides repeatedly references eggs and dried figs, while hulled fava beans, lentils, dates, and barley appear in other contexts. Whether we’re talking about corpse bits, bread or bitter herbs, Jewish tradition is a delightful smorgasbord of quantification.
So if you’re American (or Myanmarese or Liberian), using imperial units definitely comes with challenges, and I pity anyone who has to convert teaspoons to tablespoons to gills to pints to quarts to gallons. But surely it pales in comparison to figuring out if an olive-bulk of corpse flew overhead in the mouth of a bird. But if you’re feeling bold and want to be a trailblazer, perhaps you should make a switch: Start invoking the olive-bulk in your daily life (but please, not with corpse bits) and see how that goes!
Read all of Nazir 64 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on March 28th, 2023. If you are interested in receiving the newsletter, sign up here.