What is the verse from which it is derived that a fetus is administered an oath on the day of its birth? “Upon You I have relied from birth; You are He Who took me out [gozi] of my mother’s womb” (Psalms 71:6). From where may it be inferred that this word: “Gozi,” is a term of administering an oath? As it is written: “Cut off [gozi] your hair and cast it away” (Jeremiah 7:29), which is interpreted as a reference to the vow of a nazirite, who must cut off his hair at the end of his term of naziriteship.

And Rabbi Elazar says: To what is a fetus in its mother’s womb comparable? It is comparable to a nut placed in a basin full of water, floating on top of the water. If a person puts his finger on top of the nut, it sinks either in this direction or in that direction.

§ The Sages taught in a baraita: During the first three months of pregnancy, the fetus resides in the lower compartment of the womb; in the middle three months, the fetus resides in the middle compartment; and during the last three months of pregnancy the fetus resides in the upper compartment. And once its time to emerge arrives, it turns upside down and emerges; and this is what causes labor pains.

With regard to the assertion that labor pains are caused by the fetus turning upside down, the Gemara notes: And this is the explanation for that which we learned in a baraita: The labor pains experienced by a woman who gives birth to a female are greater than those experienced by a woman who gives birth to a male. The Gemara will explain this below.

And Rabbi Elazar says: What is the verse from which it is derived that a fetus initially resides in the lower part of the womb? “When I was made in secret, and I was woven together in the lowest parts of the earth” (Psalms 139:15). Since it is not stated: I resided in the lowest parts of the earth, but rather: “I was woven together in the lowest parts of the earth,” this teaches that during the initial stage of a fetus’s development, when it is woven together, its location is in the lower compartment of the womb.

The Gemara asks: What is different about the labor pains experienced by a woman who gives birth to a female, that they are greater than those experienced by a woman who gives birth to a male? The Gemara answers: This one, a male fetus, emerges in the manner in which it engages in intercourse. Just as a male engages in intercourse facing downward, so too, it is born while facing down. And that one, a female fetus, emerges in the manner in which it engages in intercourse, i.e., facing upward. Consequently, that one, a female fetus, turns its face around before it is born, but this one, a male fetus, does not turn its face around before it is born.

§ The Sages taught in a baraita: During the first three months of pregnancy, sexual intercourse is difficult and harmful for the woman and is also difficult for the offspring. During the middle three months, intercourse is difficult for the woman but is beneficial for the offspring. During the last three months, sexual intercourse is beneficial for the woman and beneficial for the offspring; as a result of it the offspring is found to be strong and fair skinned.

The Sages taught in a baraita: With regard to one who engages in intercourse with his wife on the ninetieth day of her pregnancy, it is as though he spills her blood. The Gemara asks: How does one know that it is the ninetieth day of her pregnancy? Rather, Abaye says: One should go ahead and engage in intercourse with his wife even if it might be the ninetieth day, and rely on God to prevent any ensuing harm, as the verse states: “The Lord preserves the simple” (Psalms 116:6).

§ The Sages taught: There are three partners in the creation of a person: The Holy One, Blessed be He, and his father, and his mother. His father emits the white seed, from which the following body parts are formed: The bones, the sinews, the nails, the brain that is in its head, and the white of the eye. His mother emits red seed, from which are formed the skin, the flesh, the hair, and the black of the eye. And the Holy One, Blessed be He, inserts into him a spirit, a soul, his countenance [ukelaster], eyesight, hearing of the ear, the capability of speech of the mouth, the capability of walking with the legs, understanding, and wisdom.

And when a person’s time to depart from the world arrives, the Holy One, Blessed be He, retrieves His part, and He leaves the part of the person’s father and mother before them. Rav Pappa said: This is in accordance with the adage that people say: Remove the salt from a piece of meat, and you may then toss the meat to a dog, as it has become worthless.

§ Rav Ḥinnana bar Pappa taught: What is the meaning of that which is written: “Who does great deeds beyond comprehension, wondrous deeds without number” (Job 9:10)? Come and see that the attribute of flesh and blood is unlike the attribute of the Holy One, Blessed be He. The attribute of flesh and blood is that if one puts an article in a flask, even if the flask is tied and its opening faces upward, it is uncertain whether the item is preserved from getting lost, and it is uncertain whether it is not preserved from being lost. But the Holy One, Blessed be He, forms the fetus in a woman’s open womb, and its opening faces downward, and yet the fetus is preserved.

Another matter that demonstrates the difference between the attributes of God and the attributes of people is that when a person places his articles on a scale to be measured, the heavier the item is, the more it descends. But when the Holy One, Blessed be He, forms a fetus, the heavier the offspring gets, the more it ascends upward in the womb.

Rabbi Yosei HaGelili taught: What is the meaning of that which is written: “I will give thanks to You, for I am fearfully and wonderfully made; wonderful are Your works, and that my soul knows very well” (Psalms 139:14)? Come and see that the attribute of flesh and blood is unlike the attribute of the Holy One, Blessed be He. The attribute of flesh and blood is that when a person plants seeds of different species in one garden bed, each and every one of the seeds emerges as a grown plant according to its species. But the Holy One, Blessed be He, forms the fetus in a woman’s womb, and all of the seeds, i.e., those of both the father and the mother, emerge when the offspring is formed as one sex.

Alternatively, when a dyer puts herbs in a cauldron [leyora], they all emerge as one color of dye, whereas the Holy One, Blessed be He, forms the fetus in a woman’s womb, and each and every one of the seeds emerges as its own type. In other words, the seed of the father form distinct elements, such as the white of the eye, and the seed of the mother forms other elements, such as the black of the eye, as explained above.

Rav Yosef taught: What is the meaning of that which is written: “And on that day you shall say: I will give thanks to You, Lord, for You were angry with me; Your anger is turned away, and You comfort me” (Isaiah 12:1)? With regard to what matter is the verse speaking?

It is referring, for example, to two people who left their homes to go on a business trip. A thorn penetrated the body of one of them, and he was consequently unable to go with his colleague. He started blaspheming and cursing in frustration. After a period of time, he heard that the ship of the other person had sunk in the sea, and realized that the thorn had saved him from death. He then started thanking God and praising Him for his delivery due to the slight pain caused to him by the thorn. This is the meaning of the statement: I will give thanks to You, Lord, for You were angry with me. Therefore, it is stated at the end of the verse: “Your anger is turned away, and You comfort me.”

And this statement is identical to that which Rabbi Elazar said: What is the meaning of that which is written: “Blessed be the Lord God, the God of Israel, Who does wondrous things alone; and blessed be His glorious name forever” (Psalms 72:18–19)? What does it mean that God “does wondrous things alone”? It means that even the one for whom the miracle was performed does not recognize the miracle that was performed for him.

Rabbi Ḥanina bar Pappa taught: What is the meaning of that which is written: “You measure [zerita] my going about [orḥi] and my lying down [riv’i], and are acquainted with all my ways” (Psalms 139:3)? This verse teaches that a person is not created from the entire drop of semen, but from its clear part. Zerita can mean to winnow, while orḥi and riv’i can both be explained as references to sexual intercourse. Therefore the verse is interpreted homiletically as saying that God separates the procreative part of the semen from the rest. The school of Rabbi Yishmael taught a parable: This matter is comparable to a person who winnows grain in the granary; he takes the food and leaves the waste.

This is in accordance with a statement of Rabbi Abbahu, as Rabbi Abbahu raises a contradiction: It is written in one of King David’s psalms: “For You have girded me [vatazreni] with strength for battle” (II Samuel 22:40), without the letter alef in vatazreni; and it is written in another psalm: “Who girds me [hame’azreni] with strength” (Psalms 18:33), with an alef in hame’azreini. What is the difference between these two expressions? David said before the Holy One, Blessed be He: Master of the Universe, You selected me [zeiritani], i.e., You separated between the procreative part and the rest of the semen in order to create me, and You have girded me [zeraztani] with strength.

Rabbi Abbahu taught: What is the meaning of that which is written in Balaam’s blessing: “Who has counted the dust of Jacob, or numbered the stock [rova] of Israel” (Numbers 23:10)? The verse teaches that the Holy One, Blessed be He, sits and counts the times that the Jewish people engage in intercourse [revi’iyyoteihem], anticipating the time when the drop from which the righteous person will be created will arrive.

And it was due to this matter that the eye of wicked Balaam went blind. He said: Should God, who is pure and holy, and whose ministers are pure and holy, peek at this matter? Immediately his eye was blinded as a divine punishment, as it is written: “The saying of the man whose eye is shut” (Numbers 24:3).

And this statement is the same as that which Rabbi Yoḥanan said: What is the meaning of that which is written, with regard to Leah’s conceiving Issachar: “And he lay with her that night” (Genesis 30:16)? The verse teaches that the Holy One, Blessed be He, contributed to that act. The manner in which God contributed to this act is derived from another verse, as it is stated: “Issachar is a large-boned [garem] donkey” (Genesis 49:14). This teaches that God directed Jacob’s donkey toward Leah’s tent so that he would engage in intercourse with her, thereby causing [garam] Leah’s conceiving Issachar.

§ Rabbi Yitzḥak says that Rabbi Ami says: The sex of a fetus is determined at the moment of conception. If the woman emits seed first, she gives birth to a male, and if the man emits seed first, she gives birth to a female, as it is stated: “If a woman bears seed and gives birth to a male” (Leviticus 12:2).

The Sages taught: At first, people would say that if the woman emits seed first she gives birth to a male, and if the man emits seed first, she gives birth to a female. But the Sages did not explain from which verse this matter is derived, until Rabbi Tzadok came and explained that it is derived from the following verse: “These are the sons of Leah, whom she bore to Jacob in Paddan Aram, with his daughter Dinah” (Genesis 46:15). From the fact that the verse attributes the males to the females, as the males are called: The sons of Leah, and it attributes the females to the males,in that Dinah is called: His daughter, it is derived that if the woman emits seed first she gives birth to a male, whereas if the man emits seed first, she bears a female.

This statement is also derived from the following verse: “And the sons of Ulam were mighty men of valor, archers, and had many sons and sons’ sons” (I Chronicles 8:40). Is it in a person’s power to have many sons and sons’ sons? Rather, because