Full Lecture Transcript (Cleaned)
The Question — 0:00
Brother Muammar from Moscow, Russia emails about a troubling hadith. He says it states that the gender of a baby is determined by whether the man or woman discharges first — and he asks how this can be reconciled with our modern understanding of genetics.
Yasir Qadhi first notes that Russia has a large Muslim population — perhaps 7-10% — with mosques and halal restaurants in every major city.
The Tawban Hadith — 3:00
The hadith in question is in Sahih Muslim, narrated by Tawban, the freed slave of the Prophet ﷺ. A Jewish rabbi came to the Prophet and asked him several questions, one of which concerned the baby's origin. The Prophet ﷺ said: "The fluid of the man is whitish, and the fluid of the woman is yellowish. When they come together, if the man's fluid overpowers (sabaka) the woman's, the child becomes male by Allah's permission; if the woman's fluid overpowers the man's, the child becomes female."
Modern genetics establishes definitively that the baby's gender is determined entirely by the male sperm — specifically, whether it carries an X or Y chromosome. The female egg plays no role in determining gender. So this hadith appears to say something incorrect.
The Methodology for Such Hadith — 5:00
Yasir Qadhi explains the proper scholarly methodology when encountering a hadith that seems to conflict with established knowledge:
Step 1: Verify the authenticity of the hadith — is it actually authentic? (In this case, yes — the chain is sound.)
Step 2: Gather all narrations of the same incident. Hadith were narrated by meaning, not word-for-word, meaning narrators conveyed the gist using their own words. Different narrators of the same event may use different words, and sometimes a narrator's word choice inadvertently changes the meaning.
The Anas Narration in Bukhari — 8:00
Imam al-Bukhari — whose meticulous care in hadith selection is unparalleled — did not choose the Tawban narration. He chose the narration of Anas ibn Malik, which records the same incident with a crucial difference.
In Anas's narration, the rabbi is identified as Abdullah ibn Salam, the chief rabbi of Madinah. He says: "I'm going to ask you three things that only a prophet would know." One question he asks is: "Tell me where does the child's resemblance (shabah) come from?" — not gender.
The Prophet ﷺ responds: "If the man's fluid sabaka (dominates/overpowers) the woman's fluid, the child will resemble him. If the woman's fluid sabaka the man's, the child will resemble her."
The Word 'Sabaka' — 11:00
The Arabic word sabaka can mean "to be first" (one translator's choice) or "to dominate/overpower" (the more complete meaning). The concept of one parent's genes dominating the other's maps perfectly onto modern genetics' terminology of dominant and recessive alleles.
In genetics, every child receives two versions of each gene (alleles) — one from each parent. One allele is expressed (dominant) and the other is suppressed (recessive). Whichever parent's genes dominate, the child resembles that parent. This is precisely what the Bukhari narration describes using the word sabaka.
Ibn Taymiyyah's Observation — 13:00
Remarkably, Ibn Taymiyyah — writing 800 years ago, with no knowledge of modern genetics — noted that the Tawban narration (about gender) seemed less reliably preserved than the Anas narration (about resemblance), purely based on textual analysis. He concluded that the original question was about resemblance, and the reference to gender in Tawban's narration was likely a narrator's error in conveying the meaning.
The Broader Lesson — 16:00
Yasir Qadhi ends with an important principle: the Quran and Sunnah were not revealed as books of science. They were revealed to guide us spiritually, ethically, and theologically. The miracle of the Quran is not that it predicted every scientific discovery — it is that it is the Word of Allah guiding humanity to its purpose.
When apparent conflicts arise between hadith and science, the response is not to abandon the faith or the hadith tradition. It is to apply the proper sciences of hadith — examining chains, comparing narrations, understanding Arabic terminology — and more often than not the apparent conflict dissolves entirely.
Our certainty in Islam is based on the Quran and the existence of Allah — not on individual hadith data points. Those data points are far lower on the scale of epistemological certainty, and they should not be used to challenge what is certain.
And Allah knows best.