I speak of the traditional knowledge in Islam.
To say that everything except God is vain is to ascribe to Him everything that happens. The very first revelations of God Almighty to Muhammad (peace be upon him and his family) said:
"Read! in the name of thy Lord and Cherisher, Who created-
Created man, out of a (mere) clot of congealed blood:
The Holy Qur'an, The Clot of Blood (Surah 96) V 1-4
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Man is not created out of a clot of blood. Muhammad probably saw his wives periods, and assumed the blood was what baby's were made of.