Put off rising -- importance said to be to plan for attack (3,2,4)
I believe the answer is:
lie in wait
'be to plan for attack' is the definition.
'put off rising importance said' is the wordplay.
'put off rising' becomes 'liein'.
'importance' becomes 'weight' (weight is a kind of importance).
'said' indicates a 'sounds like' (homophone) clue.
'weight' is a homophone of 'wait'.
'liein'+'wait'='LIE IN WAIT'
'to' is the link.
(Other definitions for lie in wait that I've seen before include "Lurk" , "Set an ambush" , "Prepare to launch ambush" , "what will hunter do?" , "Hope to catch" .)