Look into payment of commission and influence (5)
I believe the answer is:
clout
'influence' is the definition.
(I've seen this in another clue)
'look into payment of commission' is the wordplay.
'look' becomes 'lo' ('lo' is an archaic exclamation meaning 'look!').
'into' means one lot of letters goes inside another.
'payment of commission' becomes 'cut' (I can't justify this - if you can you should give a lot more credence to this answer).
'lo' going inside 'cut' is 'CLOUT'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for clout that I've seen before include "Cuff" , "Whack" , "Smack - influence" , "political muscle" , "Box" .)