Sacred text omitting black humour (4)
I believe the answer is:
bile
'humour' is the definition.
(I know that bile is a type of digestive fluid)
'sacred text omitting black' is the wordplay.
I cannot quite understand how this works, but
'black' could be 'b' (as in pencil classifications) and 'b' is found within the answer.
The remaining letters 'ile' 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 bile that I've seen before include "Bitter liquid stored in gall bladder" , "Bitterness - digestive fluid stored in the gall bladder" , "Digestive juice secreted by the liver" , "Anger, bitterness" , "Spleen" .)