梵網經古迹記 2.110

2.110

述曰：菩薩應聚利有情物而畜殺具，深違愍濟，故須制也。「乃至殺父母尚不加報」者，以彼還受自宿業果，因果法爾，不應瞋故。若瞋自害，無所益故。言「犯輕垢罪」者，若護正法，即無違犯。《涅槃經》中在家護法，聽持伏故。

The Commentary states: A bodhisattva should amass objects that benefit sentient beings; keeping killing implements deeply violates pity and rescue, so it must be prohibited. Regarding 'even if one's parents are killed, one still does not exact revenge': because they are merely receiving the retribution of their own past karma, which is the intrinsic nature of cause and effect, one should not become angry. If one becomes angry, it only harms oneself and brings no benefit. Regarding 'commits a duṣkṛta offense': if it is to protect the true Dharma, then there is no violation. In the Nirvāṇa-sūtra, laypeople protecting the Dharma are permitted to carry weapons to subdue [foes].