Ready money in strong bag brought back by husband (4,4)
I believe the answer is:
hard cash
'ready money' is the definition.
(I've seen this before)
'strong bag brought back by husband' is the wordplay.
'strong' becomes 'hard' ('hard' can be a synonym of 'strong'**).
'bag' becomes 'sac' (I've seen this before).
'brought back' shows that the letters should be reversed in order.
'by' means one lot of letters go next to another.
'husband' becomes 'h'.
'sac' back-to-front is 'cas'.
'hard'+'cas'+'h'='HARD CASH'
'in' is the link.
(Other definitions for hard cash that I've seen before include "Ready money" , "Coins and banknotes - not a cheque" , "Coins and notes, not cheques or promises" , "Not plastic!" .)