Sat and ordered guy to relax (5,2,4)
I believe the answer is:
stand at ease
'relax' is the definition.
(military command)
'sat and ordered guy' is the wordplay.
'ordered' is an anagram indicator.
'guy' becomes 'tease' (I've seen this before).
'sat'+'and'='satand'
'satand' anagrammed gives 'standa'.
'standa'+'tease'='STAND AT EASE'
'to' acts as a link.
(Other definitions for stand at ease that I've seen before include "Command to troops" , "Relax (on parade ground)" , "An order to soldiers" , "letting attention go?" , "Instruction to soldiers - and sea state (anag)" .)