Listen, they'll provide an organ temporarily (4,2,3)
I believe the answer is:
lend an ear
'listen' is the definition.
(I've seen this before)
'they'll provide an organ temporarily' is the wordplay.
I cannot quite see how this works, but
'provide' could be 'lend' (I've seen this in another clue) and 'lend' is found within the answer.
'an' could be 'a' and 'a' is present in the answer.
'organ' could be 'ear' (the ear is an organ) and 'ear' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lend an ear that I've seen before include "Listen - to borrower" , "Listen attentively (to)" , "Hark" , "Follow Mark Antony" , "Pay attention" .)