On the previous occasion, got it back to me early (6,4)
I believe the answer is:
before time
'it back to me early' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'on the previous occasion got' is the wordplay.
'on' says to put letters next to each other.
'the previous' becomes 'fore' (I've seen this in another clue).
'occasion' becomes 'time' (I've seen this in another clue).
'got' becomes 'be' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'fore'+'time'='foretime'
'foretime' put after 'be' is 'BEFORE TIME'.
Can you help me to learn more?
(Another definition for before time that I've seen is " Early, premature".)