Honest, therefore, come to my assistance (2,4,2)
I believe the answer is:
so help me
'honest' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'therefore come to my assistance' is the wordplay.
I cannot quite see how this works, but
'therefore' could be 'so' ('so' can mean 'consequently' or 'therefore') and 'so' is found in the answer.
'assistance' could be 'help' (synonyms) and 'help' is found within the answer.
The remaining letters 'me' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for so help me that I've seen is " On my word".)