Order or decree (6)
I believe the answer is:
behest
I believe this is a double definition.
'order' is the first definition.
(I've seen this in another clue)
'decree' is the second definition.
(I've seen this in another clue)
(Other definitions for behest that I've seen before include "Command - Thebes (anag)" , "(At someone's) command" , "Order" , "Command, bidding" .)