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Embryology in Islamic Scripture

This article focuses on what the Islamic texts tell us in regards to embryology, rather than the apologetic spin.


The Qur'an and Sahih Hadith





Here we find the three primary stages of embryonic development as defined by the Qur’an. There is a “seed,” “drop” or “semen” phase (in Arabic, “nutfah”), followed by a “clot” or “leech-like clot” phase (in Arabic, “alaqah”), followed finally by a “morsel of flesh” or “chewed lump” phase (in Arabic, “mudghah”).

There are a handful of additional ayaat that deal with this subject, and none of them disagree with this basic scenario. Yet there is more to learn from the hadith, particularly that of Bukhari and Muslim. Again, the accounts are quite consistent, and the additional information they provide is important. The first of these tells us about developmental timing:


These exact details are also given in Sahih Bukhari 4:55:549, Sahih Bukhari 8:77:593, Sahih Bukhari 9:93:546, and Sahih Muslim 33:6390.

The key information gained from all these ahadith are that the three phases (nutfah, alaqah and mudghah) each takes 40 days, for a total period of 120 days from conception to the point at which the embryo becomes a fetus.

One additional piece of testable scientific information is available in the hadith. It has to do with the point at which gender is determined. A representative hadith would be the following from Sahih Bukhari:


This detail is repeated in Sahih Bukhari 4:55:550 and Sahih Muslim 33:6397, and all of them are quite clear that the embryo is neither male nor female until after the mudghah phase is reached, some 80 days (by Islamic counting) after conception.

So, then, these are the details of embryology as reflected in the Qur’an and the hadith.

  1. The embryo spends 40 days as a drop of sperm or seed.
  2. The embryo then spends another 40 days as a “clot” or a “leech-like clot” of blood.
  3. The embryo then spends another 40 days as a “lump of flesh.”
  4. During which the gender of the child is assigned by an angel at Allah’s direction.



Points of Discussion

Timing of Islamic Phases

Taken together, the three phases of Islamic embryology take 120 days to go from conception to the point where the embryo becomes a fetus (i.e. an identifiable human baby), or right around 17 weeks. Does this reflect what we now know about embryonic development?

The answer is patently, no. The human embryo becomes a fetus around week 9, or roughly half the time Islamic embryology requires. By day 56 the fetus is essentially a complete, though tiny, human being with all organ systems in place, and all tissues developed. This is right in the middle of what Islam calls the “alaqah” phase. In other words, the developing person is already a complete human being at a point where the hadith insists it (not he or she) still has almost three weeks remaining as a “clot of congealed blood.”

In fact, there are no developmental milestones which can be mapped to the three 40 day periods required by Islamic embryology, even though they are stressed in several authoritative ahadith.

Conclusion: The hadith is demonstrably wrong concerning the timing of embryologic development.

Description of Islamic Phases

The three Islamic phases of development are described in a very visual way, allowing for an informed evaluation of the accuracy of those descriptions. This might be expected if for no other reason than that during the Prophet’s day, there was not even the idea of a microscope, and any descriptions offered would reasonably be of objects that were visible to an unaided eye. And this is exactly what we find.

And certainly, each of the three Islamic stages is described at a visible level of scale. A drop of seed, a clot of blood, a lump of flesh; all of them are objects of a size with which the ancient Arabs would have been familiar.

The “Drop of Seed” Phase (Nutfah)

There is little to no debate among Muslims as to the meaning of the word, “nutfah.” It is a “drop of seed” or “drop of semen” of the sort that would have been familiar to any adult Arab male. The Arabs rightly understood (as did all of their non-Arab neighbors) that semen was necessary to begin the process of procreation. But, exactly as with all their non-Arab neighbors, the writers of the Qur’an and the hadith did not seem to understand that there was an egg produced by the mother that is fertilized by the male’s semen.

The Arabs believed that the woman served simply as an incubator for a child that was fully contained in the father’s seed. There was no understanding of the actual biology of sexual reproduction, and no such understanding is apparent in the Qur’an.

Instead, the Qur’an tells us that the “drop of seed” remains exactly that (a drop of seed) for the entire nutfah phase (40 days according to Bukhari and Muslim). What actually is happening during those 40 days, and how might it be said to resemble a “drop of seed?”

The actual “drop of seed” provided by the male dissipates within minutes of ejaculation, so even before conception, the literal “drop of seed” no longer exists. The case could certainly be made that the fertilized egg resembles a seed until about day 13 or fourteen, but the “drop” is long gone, replaced with a microscopic egg that moves through a period called the “blastocyst.” But by the beginning of the third week, the embryo has already begun to differentiate into a trilaminar embryo with the three layers of ectoderm, mesoderm, and endoderm. A mere two and a half weeks after conception, the embryo no longer looks anything like a “drop of seed,” while the Islamic tradition indicates that the nutfah stage should last for an additional three weeks.

By day 40 of actual embryonic development (when the “drop” stage should be just ending and the “clot” stage beginning) the embryo is actually very well advanced. Measuring some 11 millimeters long, and the nervous system is well along its development. The embryo has eyes and ears, all four limbs have begun to form, the heart bulge is prominent. It bears no resemblance at this point to either a “drop of seed” or a “leech-like clot.”

Interim Conclusion: The Qu’ran is in error describing the embryo as a “drop of seed” for any significant period of time, and certainly wrong in assigning a 40 day period to such a phase.

The “Leech-Like Clot” Phase (Alaqah)

The word “alaqah” is a bit more ambiguous than “nutfah,” and so has been translated a bit more flexibly by apologists. Although consistently translated as a “clot of blood” by multiple translators, there are a handful of instances where it is rendered as “a leech-like clot.” This is the phase that (according to Bukhari and Muslim) should last from about day 41 to day 80 after conception.

Among the many images of Allah’s creative power reflected in the Qu’ran and the hadith, the image of man having been created from a clot of blood is one of the most common, showing up over a dozen times in the Qu’ran, Sahih Bukhari and Sahih Muslim alone.

What actually is happening during those 40 days, and how might it be said to resemble a “leech-like clot?”

The period of development covered by the “alaqah” stage includes from week six until week eleven after conception. The first two weeks of this “phase” actually encompass the final two weeks of embryonic development, for at that point the baby is essentially completely formed, and from here on out is known as a fetus.

Interestingly, at no time during this period (or any period for that matter) does the embryo or fetus resemble a “clot.” And while dependence of the placenta might be described as being vaguely “leech-like” in that it is attached to the uterine wall, no one would ever confuse the embryo or fetus with a leech.

This is as good a point as any to point out that embryonic development is essentially over by day 56, or in less than one half of the time described by Islamic embryology.

For over three weeks of the supposed “alaqah” phase, rather than a “leech-like clot” the fetus is actually a fully formed human being, ranging in size from 35 mm to about 80 mm in length.

Interim Conclusion: The Qu’ran and hadith are in error describing the embryo as a “leech-like clot” for any period of time, and certainly wrong in assigning the period from 41 to 80 days for such a phase.

The “Lump of Flesh” Phase (Mudghah)

The Arabic word “Mudghah” is uniformly described as a “lump” or “morsel of flesh.” Sometimes, it is more descriptively referred to as a “chewed lump of meat.” According to the hadith, this phase would cover day 81 to 120 of fetal development, or weeks 12 through 17.

However, rather than a “lump” of anything, this period is one primarily of increasing size for the already fully formed fetus. During this period of time the fetus grows finger and toenails, begins to grow hair, and by the end of it the mother is beginning to feel the child’s movements. At no time during these weeks does the fetus look like anything other than an obvious human being.

If there were anytime during which the embryo might be described as a “lump of flesh,” that would have been much earlier, perhaps during the fourth week. But even then, the embryo was quite organized and complex, hardly “chewed” in any sense of the word.

Interim Conclusion: The Qur’an and hadith are in error describing the embryo as a “morsel of flesh” for any significant period of time, and certainly wrong in assigning the period from 81 to 120 days for such a phase.


The three Qur’anic phases are impossible to conform with actual embryonic development, and that problem is only magnified by the timing of those phases as prescribed by the hadith. There are no actual phases that can be correlated to nutfah, alaqah or mudghah, and the level of development that Islam asserts takes 120 days actually takes less than half of it.


According to multiple ahadith, it is only after the mudghah phase (days 81-120) that an angel of the Lord determines the gender of the baby. But in fact, modern genetics shows that the gender of the baby is determined at the moment of conception, and is therefore already set some four months before Islam asserts the question is even asked of Allah.

Conclusion: The authors of the Qur’an and the hadith had no idea as to the genetic nature of gender, and assumed wrongly that it was assigned by Allah months after it was actually determined by genetics. The Islamic model is wrong again.

Some Notes on the Interpretations of Dr. Keith Moore

In articles published widely across Islamic websites, Keith L. Moore goes on the record to provide a generous assessment of the Qur’an and hadith in the light of modern knowledge about embryology. But a review of his “analysis” shows the extent to which he had to twist both the Islamic scriptures and modern science in order to get the “facts” to correlate.

Specifically, Moore’s intellectual lapses are these:

1. He liberally translates Arabic into terms that no Arabic speaker would consider justified, but that allows him to pretend the Arabic is closer to truth than it really is. For example, in spite of the fact that almost three dozen translations of “alaqah” found on line never once exclude the word “clot,” Moore writes instead that “The word "alaqah" refers to a leech or bloodsucker.”

2. He completely ignores the timing of phases dictated by the hadith, for to consider them renders even his mistranslation unintelligible. For example, after mistranslating “alaqah” to mean “a leech or bloodsucker,” he then compares it to the human embryo at 24 days gestation. But 24 days is still firmly within the “nutfah” phase, when the embryo should actually look like a “drop of seed.” He does the same with “mudghah,” comparing it with the embryo at 28 days, still in the “nutfah” phase and only four days later than he had assigned to “alaqah.”


See Also

  • Embryology - A hub page that leads to other articles related to Embryology



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