献芹

verb

to offer a humble gift or shallow advice as a token of respect

Derived from a story in the Liezi (《列子•杨朱》) in which a man praised wild vegetables (戎菽、甘枲茎、芹萍子) to a wealthy villager. After eating them, the villager became sick, and the recommender was shamed. Used as a self-deprecating polite expression when presenting gifts or opinions that one considers inadequate.