Say yes, the son’s rolling in money (7)
I believe the answer is:
consent
'say yes' is the definition.
(I've seen this before)
'son's rolling in money' is the wordplay.
'rolling' indicates an anagram.
'in' is an insertion indicator.
'money' becomes 'cent' (eg denomination of dollars).
'son' with letters rearranged gives 'ons'.
'ons' going within 'cent' is 'CONSENT'.
'the' is the link.
(Other definitions for consent that I've seen before include "authorisation" , "Give permission for something" , "Agree (to do something)" , "Agree or permit" , "Permission, agree" .)