《战国策·楚四·天下合从》
更羸说： 这只雁飞得很缓慢，叫得声音又悲切；飞得缓慢是因为它旧伤疼痛；叫的悲切是因它离开了雁群，身负旧伤且心存惊惧，一听见弓弦的声音就吓得拼命高飞，以致使它的旧伤口破裂而掉落下来。 
对曰： 其飞徐而鸣悲。飞徐者，故疮痛也；鸣悲者，久失群也，故疮未息，而惊心未至也。闻弦音，引而高飞，故疮陨也。 
Gengying said: "This goose was flying slowly and crying sadly; it was flying slowly because it was suffering from an old injury; it was crying sadly because it had left the flock, and was suffering from the old injury and fearing for its life, and as soon as it heard the sound of the bowstring, it was so scared that it tried to fly high in the sky, which caused its old wound to burst and made it fall down."