《庄子·外篇·田子方》
于是伯昏无人就登上高山，脚踏险石，背对着百仞深渊向后却退，直到脚下有三分之二悬空在石外，在那里揖请列御寇退至相同位置表演射箭。
于是无人遂登高山，履危石，临百仞之渊，背逡巡，足二分垂在外，揖御寇而进之。
So Bo Hun Wu Ren climbed up the high mountain, stepped on the dangerous rocks, turned around with his back to the hundred-foot abyss and backed away, until two-thirds of his feet were hanging outside the rock, where he bowed and asked Lie Yukou to step back to the same position Perform archery.