In the Spring and Autumn Period (chūn qiū shí qī  春秋时期,770-476 BC) ,there was an expert archer in the State of Chu (chǔ guó 楚国) called Yang Youji (yáng yóu jī 养由基). To test his skill, someone chose three leaves at different heights on a willow tree, and challenged him to hit them in order. Yang Youji stood more than one hundred paces away, and hit the three leaves in order.

This idiom describes excellent marksmanship. Later it became used to indicate great and assurance.