染指于鼎

Explanation: Ding: Ancient cooking utensils made of bronze, multi-round, three-legged ears. Dip fingers in tripod in the soup. Metaphor picks Ungraded interests. 　　Source: "Zuo Xuan public four-year": "and eat sea turtle doctor, and is also called sub-public Erfu. Son of public anger, to encroach on the tripod, try the out."