《论衡·卷二·命义篇》
经传上说： 命有三种：一叫正命，二叫随命，三叫遭命。 
传曰： 说命有三，一曰正命，二曰随命，三曰遭命。 
The classics say: There are three kinds of fate: one is called "correct fate", the second is called "following fate", and the third is called "fulfilled fate".