《左传·定公·定公四年》
如果让先渡过河的楚军知道一过河就可以逃脱，后边的人羡慕先渡河的，楚军就没有斗志了。
若使先济者知免，后者慕之，蔑有鬥心矣。
If we let the Chu army on the other side of the river know that once they cross the river, they will be able to escape, the people following will envy the ones who crossed first, and the Chu army will lose the will to fight.