梵網經菩薩戒本疏 6.94

6.94

初、制意者，謂大菩提心是眾行之本、成佛之因，若忘此心則匿其萬德，既壞三聚失於五位，何菩薩之有？故須制也。

First, the intention of the formulation: the great bodhicitta is the root of all practices and the cause of attaining Buddhahood; if one forgets this mind, one conceals its myriad virtues, thereby destroying the three clusters of precepts and losing the five ranks—how could one then be a bodhisattva? Therefore, it had to be formulated.