Fifty per cent of the rabbis expect this to divide them (6)
I believe the answer is:
bisect
'rabbis expect this to divide them' is the definition.
'bisect' can be an answer for 'to divide' (I've seen this before). I am not sure about the rest of the definition.
'fifty per cent of the' is the wordplay.
I cannot quite see how this works, but
'cent' could be 'c' and 'c' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
The remaining letters 'bise' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for bisect that I've seen before include "Cut in half" , "fork" , "equally split" , "Divide in half" , "Cut twenty [IN TWO]" .)