From Sounding Clay

Then, in the third, Allah (swt) turns from what is outside to the human being himself. The human being is a biological miracle. Anyone who studies it — take a book of anatomy and begin to look at the complicated, sophisticated, elaborate design of it: how the food goes down and into the stomach, the large intestine, the small intestine, how something goes into the colon and other matter into the bladder. The large intestine has its function, to absorb certain minerals; the small intestine takes some other part; the stomach processes the food. And in each of these places various kinds of goodness are drawn out, while whatever is bad, whatever is excess, whatever is waste is then passed through. And the whole picture of it, the one-way path and the rest — it is remarkable. One could speak of that alone for a day, considering the way Allah (swt) has created it. But that must be left to the reader and to the anatomy books that may be looked at in biology.

So Allah (swt) begins to speak of the inception of man:

Wa laqad khalaqnā al-insāna min ṣalṣālin min ḥamaʾin masnūn wa-l-jānna khalaqnāhu min qablu min nāri al-samūm. So the jinn are created from fire. That is their origin. One wonders how the jinn can be created from fire when they are not aflame all the while, as though one knew. And the human being is said to be created from clay, from dirt. Yet when a man picks at himself, when he scratches himself, no dirt comes away; no soil comes out. One cannot unhinge and dissolve a human being and return him to us, unless one puts him back into the earth. What, then, does it mean to be created from soil? The angels are created from light. What does that mean? The source is the soil.

How Allah took of the soil and created Ādam (peace be upon him) was that Allah (swt) told the angel to bring him soil from different parts of the world — after the earth was created, from its different parts, so that Ādam (peace be upon him) might represent everyone. That is why from him come all shades of colour, all ethnicities, all backgrounds, and various physiques: because he comes from everywhere. Allah took that soil and blew the soul into it.