The head of the Ji Family was wealthier than the Duke of Zhou ever was, but Ran Qiu still assisted him with the collection of taxes to further increase his wealth. Confucius said: “He is no longer my disciple. You may beat the drum and attack him, my young friends.”
I don’t know if any specific incident sparked this threat of violence from Confucius, but it must have constantly galled the sage to see his disciples such as Ran Qiu and Zilu make their fortunes by working for his political nemesis Ji Kangzi while he struggled in relative poverty. So much for all the hard work he put into teaching them ethical principles!
Ran Qiu stayed behind after Confucius left his home state of Lu in 497 BC to go into exile, and on being appointed the counselor (宰/zai) of the regent Ji Kangzi helped him revive the local economy while enriching himself and his boss in the process. Despite Confucius’s vociferous condemnation of his behavior, Ran Qiu played an instrumental role in persuading Ji Kangzi to invite Confucius to come home after many years of exile.
Now that’s loyalty for you!