مِن نُّطْفَةٍ إِذَا تُمْنَىٰ 
  Min nu t fatin i tha  tumn a      out of a [mere] drop of sperm as it is poured forth,
   - Mohammad Asad
     
from a drop of ejaculated semen,
   - Muhammad Farooq-i-Azam Malik
   from a sperm-drop when it is emitted.
   - Mustafa Khattab
     
From a drop (of seed) when it is poured forth;
   - Marmaduke Pickthall
   From a seed when lodged (in its place);
   - Abdullah Yusuf Ali