梵網經菩薩戒本疏 6.48

6.48

初制意者，菩薩應大慈救物，不惜身命，何容為利？以惡法損人，別害三聚，故須制也。

First, the intention of instituting the precept: A bodhisattva should rescue sentient beings with great compassion, not begrudging body or life; how could they, for the sake of gain, injure people with evil arts, specifically harming the three clusters of precepts? Therefore, it had to be instituted.