A circular jade ring: the character "圆" (circular) sounds like "原" (original), and the character "环" (ring) sounds like "还" (return).
The Crown Prince is warning Zhang Keyuan to return Madam Shen in her original state in the future.
Zhang Keyuan was first warned by the Empress Dowager's grandniece, and then admonished by the Crown Prince's trusted eunuch. Although he had dealt with countless criminals over the years and wasn't unfamiliar with noble scions, who else had such powerful backing that could muster two influential figures to intervene on their behalf?
He was like a startled bird; how could he dare lay a finger on Shen Yinning?
Forcing a smile, he courteously escorted Gui Quan out of the Ministry of Justice. His palm, still clutching the jade ring, was drenched with sweat.
The jade ring was smooth and warm to the touch.
After years in the bureaucracy, Zhang Keyuan faintly grasped the nature of the relationship between Shen Yinning and the Crown Prince.