He left with Abraham (4)
I believe the answer is:
abel
'he' is the definition.
'left with abraham' is the wordplay.
'left' becomes 'l' (common abbreviation).
'with' means one lot of letters go next to another.
'abraham' becomes 'abe'.
'l' put after 'abe' is 'ABEL'.
(Other definitions for abel that I've seen before include "First shepherd" , "One man was murdered" , "Victim of murderer" , "Eve's son" , "Cain's victim; - Magwitch (Great Expectations)" .)