《汉书·传·货殖传》
所以，凡是智慧够不上同我这样随机应变，勇气不够坚决果断，仁义而不能正确取舍，强悍而不能坚守原则的人，虽然想学习我的生财之道，我也始终不会告诉他。 
故智不足与权变，勇不足以决断，仁不能以取予，强不能以有守，虽欲学吾术，终不告也。 
Therefore, if a person's intelligence is not enough to adapt to changing circumstances like me, their courage is not firm and decisive enough, they are benevolent but cannot make the right choices, and they are powerful but cannot adhere to principles, even if they want to learn my way of making money, I will never tell them.