Observe you accept the money (4,4)
I believe the answer is:
take note
'observe you' is the definition.
'take note' can be an answer for 'observe' (I've seen this before). I'm not sure about the 'you' bit.
'accept the money' is the wordplay.
'accept' becomes 'take' (taking is a kind of accepting).
'the money' becomes 'note' (I can't justify this - if you can you should believe this answer much more).
'take'+'note'='TAKE NOTE'
Can you help me to learn more?
(Other definitions for take note that I've seen before include "what the stenographer does" , "mark?" , "Observe closely" , "Pay attention" , "Observe and absorb - jot it down" .)