《孟子·离娄章句下·第二十四节》
庾公之斯说： 我学习射箭于尹公之他，尹公之他是向先生学习的射箭，我不忍心用先生的箭法反过来伤害先生您。
曰： 小人学射于尹公之他，尹公之他学射于夫子。我不忍以夫子之道反害夫子。
Yu Gong Zhi Si said: I learned my archery from Yin Gong Zhi, and Yin Gong Zhi learned his archery from the master, so out of respect for the master, I am reluctant to use the master's archery skills to harm the master.