Inspect sack returned where coal comes from (7)
I believe the answer is:
examine
'inspect' is the definition.
(I've seen this before)
'sack returned where coal comes from' is the wordplay.
I cannot really see how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for examine that I've seen before include "Subject to scrutiny" , "Inspect, peruse closely" , "Closely study" , "Analyse" , "Check" .)