Biblically, How Are Babies Conceived?

Conception from One Seed

Our understanding of human conception is a relatively recent development, dating to late 19^th century experiments that uncovered the role of the egg and sperm in the formation of a new life. Prior to these discoveries, the details of how and why a baby was conceived were largely a matter of conjecture.^[1]

In the Bible, the beginning of human life is presented not in medical terms, but in a theological framework: YHWH is responsible for conception, pregnancy, and birth.^[2] The predominant view concerning the human role in conception is that the man gives the seed to the woman, who then conceives the child. This idea may be based on the agricultural process: A seed is sown and then germinates in the ground.^[3]

Thus, for example, in the sotah ritual, when the suspected adulteress is found innocent, she is described as unharmed by the ritual solution that she drank, and she will bear a child because she will be sown with seed:^[4]

^{במדבר ה:כח} וְאִם לֹא נִטְמְאָה הָאִשָּׁה וּטְהֹרָה הִוא וְנִקְּתָה וְנִזְרְעָה זָרַע.

^{Num 5:28} But if the woman has not defiled herself and is pure, she shall be unharmed and shall be sown/able to retain seed.^[5]

This “one-seed” theory of conception is also present in Mesopotamian sources. For example, a Babylonian medical text describes conception in terms of the woman receiving and retaining semen:

If a woman’s womb has received the semen, she will have a male child…. If a woman’s womb has received the semen, but she does not bear: anger of the god, unhappiness. If a woman has received (semen) in (her) belly, (but) cannot retain it (inside), to calm the woman: … (Recipe follows)^[6]

The Greek philosopher Aristotle (384–322 B.C.E.) advocates a similar view of the active role of a man’s semen in conception, with the woman contributing the passive matter of the menstrual blood in which the embryo will develop:

Now it is impossible that any creature should produce two seminal secretions at once, and as the secretion in females which answers to semen in males is the menstrual fluid, it obviously follows that the female does not contribute any semen to generation; for if there were semen, there would be no menstrual fluid; but as menstrual fluid is in fact formed, therefore there is no semen.^[7]

Conception from Two Seeds

A second view of conception, the “two-seed” theory, in which both male and female contribute to conception by giving or producing seed, is also found in the ancient Near East.^[8] For example, the Ugaritic Legend of Aqhat (14^th century B.C.E.) depicts Danatiya, the wife of Dani’ilu, as actively “achieving conception” because she experiences pleasure during sexual relations:

While he is kissing his wife, there will be conception, while he is embracing her, there will be heat. She who is going to bear will ach[ieve conception], heat for the Sa[viour’s man]!^[9]

Sexual pleasure is also connected to the two-seed conception in the Greco-Roman world:

The Hippocratic work On the Generating Seed and the Nature of the Child offers as proof of dual seed the fact that both men and women experience pleasure during intercourse, linking this to the discharge of semen. The two seeds provide identical matter drawn from the entire body, with the sex of the foetus determined by the hot or cold found in its environment.^[10]

In literature from the Second Temple period, the Dead Sea Scroll Genesis Apocryphon, which retells stories from Genesis, also hints at female seed, connecting pleasure with conception. When Lamech questions the paternity of his son Noah, his wife Bitenosh uses this argument to prove that Noah is Lamech’s son:

⁹ ואמרת יא אחי ויא מרי דכר̇ לך על עדינ̇תי א ך֯◦◦[ ]◦◦

^{1QapGen ar 2:9} And she said, “O my brother and my husband, recall for yourself my pleasure … [ ]

¹⁰ ב֯ח֯ו֯ם ענתא ונשמתי לגו נדנהא ואנה בקושט כולא֯ א֯[חוינ]ך֯ [ ]◦◦◦

^2:10 in the heat of the moment, and my panting breath! I [am telling] you everything truthfully … [ ]^[11]

Is this two-seed theory of conception also found in the Bible?

The Two-Seed Theory in the Bible

Traces of a two-seed-theory might be found in YHWH’s promise of rich or abundant זֶרַע (zeraʿ) to Hagar:^[12]

^{בראשׁית טז:י} וַיֹּאמֶר לָהּ מַלְאַךְ יְ־הוָה הַרְבָּה אַרְבֶּה אֶת זַרְעֵךְ וְלֹא יִסָּפֵר מֵרֹב.

^{Gen 16:10} And the angel of YHWH said to her [Hagar], “I will greatly increase your seed/offspring, and they shall be too many to count.”

Zeraʿ can mean both “offspring” and “seed,”[13] and thus the concept of female seed may stand in the background of this promise. Rebecca is blessed in similar terms:

^{בראשׁית כד:ס} וַיְבָרֲכוּ אֶת רִבְקָה וַיֹּאמְרוּ לָהּ אֲחֹתֵנוּ אַתְּ הֲיִי לְאַלְפֵי רְבָבָה וְיִירַשׁ זַרְעֵךְ אֵת שַׁעַר שֹׂנְאָיו.

^{Gen 24:60} And they blessed Rebecca and said to her, “O sister! May you grow into thousands of myriads; may your seed/offspring seize the gates of their foes.”

The Childbirth Law

The laws dealing with the ritual or cultic impurity of a woman after childbirth begin with an uncommon verb for conception—תזריע, from the root ז.ר.ע, “to sow,” as in to plant seed:^[14]

^{ויקרא יב:ב} דַּבֵּר אֶל בְּנֵי יִשְׂרָאֵל לֵאמֹר אִשָּׁה כִּי תַזְרִיעַ וְיָלְדָה זָכָר וְטָמְאָה שִׁבְעַת יָמִים כִּימֵי נִדַּת דְּוֹתָהּ תִּטְמָא.

^{Lev 12:2} Speak to the Israelite people thus: If a woman תזריע and bears a male child, she shall be (ritually) impure seven days; like the days of her menstruation, she shall be impure.^[15]

In the Masoretic Text, תזריע is vocalized as an active hiphʿil form: תַזְרִיעַ (tazriaʿ), suggesting that the woman produces seed (more on this later.) The Septuagint (and the Samaritan Pentateuch),^[16] however, interprets the verb in a passive sense, reflecting a one-seed theory conception:

^{LXX Lev 12:2} If a woman is seeded/delivered/conceives and bears a male child, she will be impure seven days, like in the days of the separation of her menstruation she will be impure.^[17]

Is seeded – Most English translations follow the Septuagint, effectively reading תזריע as a passive niphʿal form: תִזָּרַע (tizzaraʿ), “she is seeded/delivered/conceives.” The NRSV, for example, has “if a woman conceives.” The KJV even explicitly refers to the seed implied in the Hebrew root: “If a woman have conceived seed.”

Even interpretations that retain the active character of the MT’s hiphʿil tazriaʿ (shown in bold below) often hide the concept of female seed.

Comes to term – Noting that hiphʿil verbs sometimes express completed action, David Noel Freedman translates the key phrase אִשָּׁה כִּי תַזְרִיעַ וְיָלְדָה זָכָר as “when a woman comes to term (i.e., at the completion of her pregnancy) and delivers a male.”^[18]

Bears a child – Arguing that the noun זֶרַע can refer to seeds or fruit, some translators interpret tazriaʿ as carrying a general sense of bearing a child or offspring.^[19]

Is at childbirth – Taking the verbs תַזְרִיעַ (tazriaʿ) and יָלְדָה (yaledah) as parallel terms, the NJPS understands the whole procedure as a general description of birth: “when a woman at childbirth bears a male.”

The MT

Despite these alternative approaches, tazriaʿ most likely reflects the two-seed theory that women actively contribute to conception. The hiphʿil form of ז.ר.ע occurs only in Leviticus 12:2 and in the first creation account, where it refers to plants that produce seed:^[20]

^{בראשׁית א:יא} וַיֹּאמֶר אֱלֹהִים תַּדְשֵׁא הָאָרֶץ דֶּשֶׁא עֵשֶׂב מַזְרִיעַ זֶרַע עֵץ פְּרִי עֹשֶׂה פְּרִי לְמִינוֹ אֲשֶׁר זַרְעוֹ בוֹ עַל הָאָרֶץ וַיְהִי כֵן.

^{Gen 1:11} And God said, “Let the earth sprout vegetation: plants bearing [mazriaʿ] seed, fruit trees of every kind on earth that bear fruit with the seed in it.” And it was so (cf. v. 12).

In the context of human conception, hiphʿil tazriaʿ would describe the woman as producing or bringing forth seed, not conceiving seed.^[21]

Female Seed: New Testament and Talmud

The New Testament links Sarah with the usually male-connotated terminology of seed:

^{Hebr 11:11} Through faith also barren Sarah herself received power to produce/immerse seed,^[22] even though she was past age, because she judged him faithful who had promised.^[23]

The Talmud also takes the idea of female seed for granted. For example, it explains that after Abimelech takes Sarah into his house and YHWH closes the women’s wombs (Gen 20:18), the repetition of the root ע.צ.ר, “to hinder, restrain” (עָצֹר עָצַר) refers to two closures of the womb—one for some kind of a seminal emission by the woman and one for birth.^[24]

^{בבלי בבא קמא צב.} ״כי עצר עצר ה׳״ – אמר רבי אלעזר: שתי עצירות הללו למה? אחת באיש – שכבת זרע, שתים באשה – שכבת זרע ולידה.

^{b. Qam. 92a} “For YHWH had closed fast” (Gen 20:18) – Rabbi Elazar says: “Why these two closures? One in the man—seminal emission, and two in the woman—seminal emission and birth.”

According to another Talmudic passage, three entities contribute to the genesis of a child: the father, the mother, and God:

^{בבלי נדה לא.} תנו רבנן שלשה שותפין יש באדם הקב"ה ואביו ואמו אביו מזריע הלובן שממנו עצמות וגידים וצפרנים ומוח שבראשו ולובן שבעין.

^{b. Nid. 31a} The rabbis taught: Three participate in the human being: The Holy One, his father and his mother. His father sows the white [substance], from which bones, fibers, and nails [are made], the brain in his head and the white in the eye.

אמו מזרעת אודם שממנו עור ובשר ושערות ושחור שבעין.

His mother sows the red [substance], from which skin, flesh and hair [are made], and the black in the eye.

והקב"ה נותן בו רוח ונשמה וקלסתר פנים וראיית העין ושמיעת האוזן ודבור פה והלוך רגלים ובינה והשכל.

God gives him spirit and soul, the form of the face, sight of the eye and sound of the ear, voice of the mouth, movement of the legs, understanding and intelligence.

Thus, both man and woman give some kind of semen or seed—expressed with two active forms (hiphʿil and piʿel) of the root ז.ר.ע—while God gives spirit and soul. The idea of the blood of menstruation containing some kind of semen that is mixed with the male sperma might reflect a discussion with Aristotelian concepts,^[25] but the active verb forms suggest a two-seed theory.

Male and Female Seed

The idea of female semen was widespread in the ancient world and into the middle-ages, and it is present in several biblical texts. Although the division male–female is a basic concept in the Bible, texts like Leviticus 12:2 might contain some potential to overcome gender stereotypes, because they do not convey a male-dominated understanding of conception that limits the woman’s role to giving birth, but rather present an image in which men and women are both active contributors to procreation.