Overview
Bechorot 8 contains two very different sections:
- A discussion of animal reproduction, gestation periods, and the relationship between different species.
- The beginning of the famous encounter between Rabbi Yehoshua ben Chananiah and the Sages of Athens, who challenge one another with riddles and arguments.
Dolphins and Other Sea Creatures
The Gemara teaches that dolphins reproduce like human beings. Rav Yehudah explains that the term refers to certain humanlike sea creatures.
The Gemara then explores a broader biological distinction:
- Creatures whose male reproductive organs are external give birth to live young.
- Creatures whose reproductive organs are internal lay eggs.
The Gemara initially formulates this principle in terms of the location of the eggs, but revises it after considering different types of geese.
Time of Mating and Time of Birth
The Gemara teaches that an animal generally gives birth during the same part of the day in which it mates:
- Animals that mate by day give birth by day.
- Animals that mate by night give birth by night.
- Those that mate both by day and night may give birth at either time.
Examples include:
- The chicken, which mates and lays during the day.
- The bat, which mates and gives birth at night.
- Human beings and similar creatures, which may do so by day or night.
An Egg Found on Yom Tov
This principle has a practical application.
If someone checked a chicken’s nest before Yom Tov and found no egg, but found an egg there the next morning, the egg may still be permitted.
The Gemara reasons that perhaps:
- The inspection was incomplete, or
- Most of the egg had emerged before Yom Tov and then returned inside.
Rabbi Yochanan teaches that once most of an egg emerged before Yom Tov, it is considered to have been laid before Yom Tov, even if it subsequently returned.
Which Species Can Reproduce Together?
The Gemara states:
Species whose mating procedure and gestation periods correspond can reproduce and raise offspring together.
If their basic reproductive patterns differ, they cannot normally reproduce together.
This develops the previous daf’s discussion concerning mating between different species.
Face-to-Face Mating
Most animals mate with one facing the back of the other. The Gemara identifies three exceptions that mate face-to-face:
- Fish
- Human beings
- Snakes
The Sages of Eretz Yisrael explain that these three were distinguished because the Divine Presence spoke with them.
A camel is described as mating back-to-back.
Gestation Periods
The Gemara records a series of gestation or reproductive periods and compares each animal with a corresponding plant:
- Chicken: 21 days, corresponding to the hazelnut.
- Dog: 50 days, corresponding to the fig.
- Cat: 52 days, corresponding to the mulberry.
- Pig: 60 days, corresponding to the apple.
- Fox and creeping creatures: six months, corresponding to grain.
- Small kosher livestock: five months, corresponding to the grapevine.
- Large non-kosher livestock: twelve months, corresponding to the date palm.
- Large kosher livestock: nine months, corresponding to the olive.
- Wolf, lion, bear, leopard, bardelas, elephant, monkey, and owl-like creature: three years, corresponding to the bnot shuach tree.
- Viper: 70 years, corresponding to the carob.
- Snake: seven years.
The Gemara seeks a scriptural basis for the snake’s seven-year period.
The Curse of the Snake
The verse states:
“Cursed are you more than all livestock and more than all the beasts of the field.”
The Gemara compares the reproductive periods of animals and concludes that the snake’s curse extended its gestation to seven years.
The unusual length of its gestation expresses the severity of the punishment it received after the sin in Gan Eden.
The Emperor’s Challenge
The emperor asked Rabbi Yehoshua ben Chananiah:
How long is the snake’s gestation?
Rabbi Yehoshua answered:
Seven years.
The emperor challenged him from the Sages of Athens, who claimed to have observed snakes producing young after only three years.
Rabbi Yehoshua explained that those snakes had already been pregnant for four years before the Athenians began observing them.
When the emperor said that the snakes continued mating during that period, Rabbi Yehoshua answered that snakes can mate during pregnancy, like human beings.
The emperor then challenged Rabbi Yehoshua:
If you are wiser than the Sages of Athens, go defeat them and bring them to me.
Preparing to Bring the Sages of Athens
Rabbi Yehoshua asked the emperor to prepare:
- A ship containing sixty compartments.
- Sixty cushions in each compartment.
He then traveled to Athens and sought the hidden entrance to the academy.
Finding the Entrance
Rabbi Yehoshua encountered a butcher skinning an animal and asked whether the butcher’s head was for sale.
The butcher agreed, assuming Rabbi Yehoshua meant the animal’s head.
Rabbi Yehoshua then used the misunderstanding to pressure him into revealing the concealed entrance to the academy.
The butcher feared that anyone who revealed its entrance would be killed, so Rabbi Yehoshua instructed him to carry a bundle of reeds and stand it upright near the entrance as though stopping to rest.
The Guards at the Entrance
The academy had guards positioned both inside and outside:
- If they saw footprints entering, they would kill the outside guards.
- If they saw footprints leaving, they would kill the inside guards.
Rabbi Yehoshua reversed his sandals, confusing the direction of his footprints and causing the guards to turn against one another.
He then entered the academy.
Meeting the Sages of Athens
Rabbi Yehoshua found:
- The younger Sages seated above.
- The older Sages seated below.
He avoided greeting either group first, since each group might resent his apparent preference for the other. Instead, he offered a general greeting.
He introduced himself as:
The Sage of the Jews who had come to learn their wisdom.
They agreed that whoever lost the intellectual contest would submit to the winner.
The Riddles Begin
The Rejected Suitor
They asked:
What should a man do if he sought to marry a woman and she rejected him?
Rabbi Yehoshua answered with a symbolic demonstration. He inserted a peg into a low place where it did not hold, but it held when placed higher.
His meaning was:
The man may find a more suitable match elsewhere, even among those of apparently higher standing.
The Borrower Whose Property Was Seized
They asked:
Why would someone borrow again after a previous creditor seized his property?
Rabbi Yehoshua compared him to a man cutting wood:
- He cut one bundle but could not lift it.
- He continued cutting and adding more.
- Eventually someone came along and helped him lift everything.
Likewise, the borrower hopes that additional resources or assistance will eventually enable him to resolve the entire burden.
Fabricated Tales
The Athenians asked Rabbi Yehoshua to tell them something false.
He responded:
A mule once gave birth, and the newborn carried a document declaring that it was owed one hundred thousand zuz by its father’s household.
They objected:
A mule cannot give birth!
He replied:
You asked for a fabricated tale.
How Is Spoiled Salt Salted?
They asked:
If salt spoils, with what can it be salted?
Rabbi Yehoshua answered:
With the placenta of a mule.
They objected that a mule has no placenta.
He responded:
And does salt ever spoil?
The question itself was impossible, so his answer matched it.
Building a House in Midair
They challenged him:
Build us a house in the air.
Rabbi Yehoshua pronounced a Divine Name and suspended himself between heaven and earth.
He then told them:
Pass up the bricks and mortar.
The impossibility had shifted back onto them.
Finding the Center of the World
They asked him to identify the world’s center.
He pointed to a location and declared:
Here.
When they demanded proof, he replied:
Bring ropes and measure it.
The burden of disproving his answer now rested on them.
A Well Brought into the City
They told him:
We have a well in the field. Bring it into the city.
He responded:
Make ropes from bran, and I will pull it in.
Once again, their impossible demand received an equally impossible condition.
Repairing a Broken Millstone
They asked him to sew together a broken millstone.
He answered:
First spin thread from the millstone itself, and I will sew it.
Harvesting a Field of Knives
They asked:
With what does one harvest a field of knives?
He answered:
With a donkey’s horn.
When they objected that donkeys have no horns, he replied:
And is there such a thing as a field of knives?
Identifying Eggs and Cheese
They brought him two eggs and asked which came from a black hen and which from a white hen.
He brought two pieces of cheese and asked them which came from a black goat and which from a white goat.
Their question was no more answerable than his.
Where Does the Spirit Leave a Dead Chick?
They asked:
Through which opening does the spirit leave a chick that dies inside its shell?
He answered:
Through the same opening by which it entered.
A Vessel Not Worth Its Expense
They asked him to show them an object whose cost or burden exceeded its value.
They brought a large mat that could not pass through the doorway.
Rabbi Yehoshua told them to demolish the entrance to bring it through.
The mat’s inconvenience and associated cost exceeded its worth.
The Capture Begins
The daf ends as Rabbi Yehoshua tricks the Athenians into entering the prepared ship. Each entered a separate compartment and assumed the others had already gone inside.
Rabbi Yehoshua then took earth from Athens with him, preparing for the continuation of the story on the next daf.
Big Idea of the Daf
Bechorot 8 moves from patterns in nature to a contest of wisdom. Its two halves share a theme:
True wisdom involves recognizing the internal order of creation and exposing the hidden assumptions behind a question.
Rabbi Yehoshua does not merely answer riddles. He demonstrates that an impossible or dishonest premise deserves to be answered by revealing its own contradiction.