Surah 23

Surah 23:14

"then We made a clot (from) the drop, then We made a lump (from) the clot, then We made bones (from) the lump, then We clothed the bones (with) flesh, (and) then We (re)produced him as another creature. So blessed (be) God, the best of creators!"
Embryology
The verse claims the embryo forms from a congealed blood clot ('alaqa') and that bones are created first before being clothed with flesh. Scientifically, there is no 'blood clot' stage in human embryonic development, and bone and muscle tissue (mesoderm) develop simultaneously, not sequentially.