Prepare to attack Sunday morning choice, perhaps spoken mass (3,2,4)
I believe the answer is:
lie in wait
'prepare to attack' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lie in wait that I've seen before include "as some bushwhackers do" , "hover" , "Lurk" , "Set an ambush" , "Be prepared to ambush" .)