Hadith on Child Resemblance: Classical and Genetic Proof
The hadith stating that a child’s resemblance depends on whose semen prevails deals with the subject of resemblance between a child and his relatives in a brief and simple manner, yet it does not contradict modern science. The hadith aligns precisely with modern genetics when understood through its classical terminology and the concept of genetic predominance, taking into account the language of the era in which the hadith was mentioned. The Prophet’s description reflects a simplified but accurate understanding of what modern science identifies as dominant and recessive inheritance.
The hadith states that if the man’s semen rises above the woman’s semen, the child will resemble his paternal uncles, and if the woman’s semen rises above the man’s semen, the child will resemble his maternal uncles. Critics argue this contradicts modern genetic science because it implies a mechanism unknown to biology.
Terminology of the Hadith
The hadith uses terminology suited to its era, which corresponds to modern biological concepts. The man’s semen refers to the seminal fluid that contains sperm, which are responsible for transferring genetic material (X or Y chromosomes). The woman’s semen refers to the reproductive secretions that prepare the egg for fertilization, or the egg itself that contains the woman’s genetic material (X chromosome).
The water’s rise is understood as the predominance or the strongest influence in determining the genetic characteristics of the child.
Genetic Principles and the Hadith
The hadith refers to the subject of resemblance, which is determined based on the genetic interaction between the father and mother. This is in perfect harmony with the principles of modern genetics. Hereditary traits are determined by DNA, which consists of 23 chromosomes from the father and 23 chromosomes from the mother. Some genes are dominant, meaning their traits are clearly expressed, while others are recessive and only appear in the absence of the dominant genes.
If the dominant genes from the father are stronger, the child will resemble the father or his paternal uncles. If the dominant genes from the mother are stronger, the child will resemble the mother or his maternal uncles. These principles are documented in standard genetic references such as MedlinePlus Genetics and Genome.gov.
[!research] Study: Nature (2020) — s41586-020-2649-2
A study published in Nature magazine confirms that the resemblance between a child and the father’s or mother’s relatives depends on a complex combination of genetic genes, as the dominant genes affect the appearance of certain traits.
The Scientific Interpretation
“The man’s or woman’s semen is high” refers to the superiority of the dominant genes from one party — the father or the mother — in determining genetic traits. Apparent traits such as facial features, eye color, or hair color are determined based on the dominant genes.
The hadith accurately describes a genetic mechanism that was not known at the time of the Prophet (peace be upon him). The connection between “the man’s semen” and resemblance reflects a simplified understanding of what we know today about the influence of dominant and recessive genes. The Prophet (peace be upon him) used simple language that suited those he addressed at the time, but the scientific meaning matches what modern science has proven.
The Prophetic Knowledge Behind the Hadith
That the hadith accurately describes a genetic mechanism unknown in the seventh century is significant. The connection between “the man’s semen” and resemblance reflects a simplified understanding of what we know today about the influence of dominant and recessive genes. The Prophet (peace be upon him) used simple language that suited those he addressed at the time, but the scientific meaning matches what modern science has proven. This precision in describing hereditary mechanisms — without the tools of modern biology — points to knowledge beyond human capability at the time.
Gender Determination: The Supporting Hadiths
In the human cell there are 23 pairs of chromosomes; one pair is what determines the sex of the fetus. The genetic makeup of the male is XY, while the genetic makeup of the female is XX. Fertilization occurs when the male fluid (sperm) meets the female fluid (ovum). If the man’s fluid carries the Y trait, the baby will be a boy, God willing (X + Y). However, if the man’s fluid carries the X trait, the baby will be a girl, God willing (X + X). The coming of the fetus, male or female, has a cause after God Almighty’s permission, and this cause is connected to the man and the woman together, and not to one of them without the other.
Grade: Sahih
This narration establishes that the order and predominance of the parental fluids influences the outcome of conception.
Grade: Sahih
Here the Prophet describes the physical characteristics of the fluids and links the predominance of one over the other to gender determination.
Grade: Sahih
This hadith directly addresses the doubt about resemblance, confirming that whichever fluid prevails determines whether the child resembles the paternal or maternal line.
Grade: Hasan — classified as such by Sheikh Shu’ayb in his commentary on Al-Musnad
The common meaning between these words, which is intended, is predominance and encompassing. If the man’s water prevails over the woman’s water and encompasses it, the child will be a boy. When the opposite happens, the opposite happens. It is not possible that what is intended is the precedence of ejaculation — meaning that if the man’s ejaculation precedes it, the child will be a boy, and if the woman’s ejaculation precedes it, the child will be a girl — because this meaning does not agree with the word “predominantly” on the one hand, and is not supported by certain reality on the other hand.
Classical Scholarly Commentary
[!scholar] al-Hafiz Ibn Hajar al-Asqalani — Fath al-Bari (7/273)
What is meant is encompassing. And it is as if what is meant by the height is that which is the cause of the resemblance according to the abundance, such that the other becomes immersed in it, and thus the resemblance occurs.
Ibn Hajar further explains that al-Qurtubi interpreted the hadith of Thawban as referring to precedence, but Ibn Hajar holds that what appears correct is the interpretation of “height” in Aisha’s hadith as predominance, while in Thawban’s hadith the “height” remains as it appears. Precedence is a sign of masculinity and femininity, and the height is a sign of resemblance, so the problem is removed. And it is as if what is meant by the height is that which is the cause of the resemblance according to the abundance, such that the other becomes immersed in it, and thus the resemblance occurs. And that is divided into six sections:
First: The man’s semen precedes and is more, so it becomes masculine and similar.
Second: The opposite — the woman’s semen precedes and is more, so the child becomes feminine and similar.
Third: The man’s semen precedes, but the woman’s semen is more, so masculinity and similarity occur for the woman.
Fourth: The opposite — the woman’s semen precedes, but the man’s semen is more, so femininity and similarity occur for the man.
Fifth: The man’s semen precedes and they are equal, so it is masculine and not specific.
Sixth: The opposite — the woman’s semen precedes and they are equal, so it is feminine and not specific.
[!scholar] Ibn al-Qayyim — Tuhfat al-Mawdud bi-Ahkam al-Mawlud (p. 221)
The second matter: The precedence of one of the two waters is a reason for the resemblance of the one whose water came first, and the elevation of one of them is a reason for the child’s similarity to the one whose water came first. So here there are two matters: precedence and elevation, and they may agree or differ. If the man’s water comes first and rises above the woman’s water, the child will be a boy, and the resemblance is for the man. If the woman’s water comes first and rises above the man’s water, the child will be a girl, and the resemblance is for the mother. If one of them comes first and the other rises, the resemblance is for the one whose water came first, and the males and females are for the one whose water came first.
The hadith does not contradict modern science, but rather is completely consistent with the rules of genetics, which show that resemblance is determined by the dominant genes from the father or mother. “The height of the water” expresses the influence of the stronger genes, and has nothing to do with the amount of semen or the woman’s secretions. This agreement between the hadith and science proves that it is a divine revelation, because this information was not known to humans at the time the hadith was revealed.