《史记·七十列传·龟策列传》
能见，首仰足肣，敛胜有外；见不到，足开首仰。
见，首仰足肣，肣胜有外；不见，足开首仰。
Possible to meet, the head looks up and the feet are bent, restraining victory and something external; not possible to meet, the feet are open and the head looks up.