Hi Dave, of course we would say it's ridiculous to us today. That's because we know better but 2000-years ago this was medical "science".
This sounds to me like something out of an Islamic hadith. (I don't know if it's in the Koran? I know Koranic passages about what exactly is hijab are debated.)
Much of the information that is in the Koran came out of the Talmud; and so yes. I went and looked this up and sure enough; the whole "hair and genitalia" thing is in Talmudic teachings. (There's a lot of weird, gross and blasphemous stuff in the Talmud.)
Here's a link if anyone cares to read some rabbi's opinion.
Hair - שֵׂעָר
All this being said; regardless of what Aristotle, Socrates or anyone else thought or said, the real author of the Scripture is the Holy Spirit. Holy men of old spoke (wrote) as they were moved by the Holy Ghost.
So, considering how the Holy Spirit would know how humans are "assembled"; we see some interesting things (misinterpretations and mistranslations) show up in the Scripture.
Hebrew is an interesting language; in that it's a descriptor language and not one of word nuance. The word translated "kidney" in Hebrew comes through a couple of "add ons" to a prime word that means "to be complete, at the end, finished, accomplished" or "spent". Now in some places in Scripture "kidney" is actually a reference to reproductive organs. The second "add on" to the word brings it to mean "an article, utensil or vessel". Its translated anywhere from "armor" to "jar". What it's translated as, is understood by the context of the passage.
"Saul brought his
sword to the battle."
"Joseph dawned his
robe."
"12 sons came from the
bowels / loins of Jacob."
"place the fat with the
kidneys upon the alter"
So "vessel" / "vital organ" / "kidney". makes contextual sense as one works through the word "add ons".
Now one of the misunderstandings of the ancient world was the belief that sperm somehow passed through the kidneys. Now if one were to dissect an animal; I could see why they would make that mistake in their understanding of anatomy. The kidneys are connected to the bladder which is the last "organ" prior to exiting the body. Now obviously God knows kidneys create urine.
So the Hebrew being the type of language it was; could be adequately utilized by God (because of its ambiguity as a language of description) and still portray something in "common terms" that later on could be applied medically when humanity had obtained better understanding of how things worked.
For example; (I believe it's in Luke) the account of the angel telling Mary she will bear a son. She asks him how is this possible when she hasn't known a man. Now couched in the angel's response is an explanation that Mary would understand; but also us 2000 years later who know about DNA.
The angel's explanation entails telling Mary that God will use "the stock" of her to create this child. Now you can't see that in the English, but it is implied in the structure of the Greek.
Now she would have understood her stock as her ancestry; particularly being "of one of the tribes of Israel" going back to Jacob and then Abraham. And she knew the promise was to come through a certain "line". Her "stock" or "ancestry" or what we might say today; her DNA.
Now for those who understand how conception medically happens; it gives us a fascinating insight as to how Jesus's body was actually created by the Holy Ghost. Besides being fully God; Jesus was also fully human. A female egg has all 46 chromosomes before its fertilized. Once fertilization happens; the egg releases a polar body of excess DNA. So the Holy Spirit working with the "stock" of Mary that was already present, did not need to "add" DNA. All that would make Jesus fully human was already there.
So there is an example of how understanding of the text can increase over time as humans have greater access to knowledge of how this creation was "put together".
So in all that; obviously the Holy Spirit knows hair has nothing to do with sperm, sex or anything like that; so regardless of what Paul may have been exposed to in the teachings of men, we still interpret Scripture by Scripture and not by some cultural interpretation from 2000 years ago.