Where baby Moses was found
I believe the answer is:
nile
'where baby moses was found' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nile that I've seen before include "Cleopatra's river" , "Line (anag)" , "River (which is originally blue and white)" , "'The longest river, blue and white (4)'" , "Take a line to the river" .)