Craving is Like a Beautiful Flower

"Oh good man! Why do we say that a viper lives in a beautiful flower? For example, a man, by nature, loves beautiful flowers. He does not notice a worrying viper anywhere. He steps forth, catches hold the flower, gets bitten by the viper and dies. The same is the case with all common mortals. They devour the flowers of the five desires. Not seeing the viper within craving, they are captured. Bitten by the viper of craving, they die and get reborn in the unfortunate realms. It is otherwise with the Bodhisattva. This is why we say that it is as in the case of 'a beautiful flower in which hides a viper’."

Read More on the Nirvana Sutra, Chapter 20 - On Holy Actions 2.