《孟子·告子章句下·第七节》
第一次盟会，就共同宣称： 诛杀不孝，不轻易改变太子，不以妾为正妻。 
初命曰： 诛不孝，无易树子，无以妾为妻。 
At the first assembly, they jointly declared: kill the unfilial, don't change the crown prince easily, don't make a concubine the regular wife.