. Something too troublesome to eat yet a shame to discard. This is an example of a xiehouyu
The story comes from the Romance of the Three Kingdoms. The great Cao Cao once gave this as a command to his army as they faced the town of Hanzhong. After some discussion among themselves, his officers realized he meant the game was not worth the candle and intended to leave Hanzhong untouched.
(Cao Cao often played word games with people, adding perplexity to their fear of him.)
This expression remains in current use.
I've thought of a related expression: The Song dynasty poet Su Dongpo criticized the Tang poet Meng Jiao, saying that reading his poetry was like eating tiny crabs - hardly worth the effort.
Other Chinese literary allusions