梵網經菩薩戒本疏 4.14

4.14

First, regarding the purpose of the prohibition, it is briefly due to ten intentions: 1. Among afflictions, it is the gravest, nothing preceding this; 2. It also constitutes a course of karma that is a cause for evil destinies; 3. It burns away all roots of goodness from past lifetimes; 4. It can form great animosities that are difficult to resolve for successive kalpas; 5. Because of this, one can harm various sentient beings; 6. Even up to being able to commit crimes of immediate retribution; 7. It can obstruct the bodhisattva's kṣānti-pāramitā; 8. It harms the great compassion of bodhisattvas; 9. It causes sentient beings who are to be transformed to abandon and depart; 10. It fully brings about hundreds of thousands of obstacles. The Avataṃsaka Sūtra cites this extensively. It also says: "I do not see a single evil phenomenon that exceeds a single angry thought of a bodhisattva." Since the harm is so severe, it must be prohibited.