瑜伽論記 6.177

6.177

泰又解云：佛法如水，破戒苾芻，如水眾雜穢蝸牛，又如狗好聲如螺。然有狗行，破戒苾芻，形相似實，實性惡行。

Tai also explains: 'The Buddha-Dharma is like water; precept-breaking monks are like water's foul snails. Furthermore, like dogs with fine voices like conches yet possessing dog-like conduct, precept-breaking monks appear genuine in outward form, but in their actual nature engage in evil conduct.'