Act prematurely and clear article by Rod (4,3,3)
I believe the answer is:
jump the gun
'act prematurely' is the definition.
(I've seen this before)
'clear article by rod' is the wordplay.
'clear' becomes 'jump' (as in clearing or jumping a fence).
'article' becomes 'the' (the definite article in English).
'by' says to put letters next to each other.
'rod' becomes 'gun' (rod can mean a pistol).
'jump'+'the'+'gun'='JUMP THE GUN'
'and' is the link.
(Other definitions for jump the gun that I've seen before include "Leave too early" , "Come too early out of the starting blocks?" , "Be too hasty" , "Start too quickly" , "Act prematurely" .)