菩薩戒本疏 2.33

2.33

Seeing and thinking of weapons inevitably leads to gradual habituation; hence it was prohibited for thorough prevention. That is, it is the correct practice and guarding of the various śikṣāpadas, highlighting the abandonment of evil deeds to accomplish the accumulation of good. It is prohibited for both the Mahāyāna and Hīnayāna, forbidden to both monastics and laity. If noble persons, kings, princes, and the like wish to defend against external dangers and prepare bows and arrows, it should reasonably be permitted, but they must not reach the point of harming or killing. Furthermore, even if one is not a noble person, if one wishes to protect the Dharma and prepares weapons for defense without the mind to harm, it should also be permitted. In the Nirvāṇa-sūtra, householders are permitted to hold weapons for the sake of protecting the Dharma, but they must not reach the point of killing; the explanation of the text is easy to understand.