Which book does reciprocity come from?

The ancient origin of this idiom is The Book of Rites, which was written by Dai Sheng, a ritual scholar in the Western Han Dynasty. The content of this Confucian classic mainly focuses on the ritual system in the pre-Qin period, which embodies the philosophy and educational thought of Confucianism in the pre-Qin period. What are the allusions to extend information and exchange politeness?

The protagonist of this idiom is Confucius. During the Spring and Autumn Period, Confucius invited his disciples to give lectures at home, which attracted Lu's attention and often went to the palace to give lectures. Yang hu, the manager of Gifford, went to visit Confucius specially, but Confucius made an excuse not to see him. A roast suckling pig was specially left for Confucius. Knowing that Confucius was the most polite, I finally got a return visit from Confucius.