This allusion can be found in Zhuangzi Xiaoyao, saying to Yao: "Although a person can't be cured, a corpse hopes to take his place."
The man is a chef, who is responsible for slaughtering three animals (cattle, sheep and pigs) and catering.
A corpse is a priest who is responsible for sacrificial ceremonies and praying to ghosts and gods.
In ancient times, people had to clean up the three sacrifices and prepare tributes. The corpse is also responsible for sorting out sacrificial vessels. Then, pour the wine into the jar, put the three killed animals on the table, and then the sacrificial ceremony began. If you can't cure me, I can't go beyond my duty to take my place.