“It’s daylight,” the child said (3)
I believe the answer is:
sun
'it's daylight' is the definition.
(I've seen this in another clue)
'child said' is the wordplay.
'child' becomes 'son' (male child).
'said' shows a homophone (sound like).
'son' sounds like 'SUN'.
'the' acts as a link.
(Other definitions for sun that I've seen before include "Dawn riser" , "Earth's nearest star" , "Star that provides light and heat for a solar system" , "Shiny" , "Source of daylight" .)