佛說盂蘭盆經疏 2.48

2.48

The Tripiṭaka Master says: 'A single thread cannot restrain an elephant; it must rely on many strands. A single person cannot eliminate karma; it must depend on the multitude of virtues.' Now, carefully examining the earlier and later texts of the sūtra, when contrasting heterodox and orthodox, single and many, there are four propositions: First, orthodox but not many: this cannot rescue, hence the earlier 'it is not something the power of you alone can do anything about.' Second, many but not orthodox: this also cannot rescue, namely the aforementioned 'spirits, deities, demonic spirits, non-Buddhists,' and so forth. Third, both many and orthodox: only then can rescue take place, namely the saṅgha of the ten directions. Fourth, neither many nor orthodox: evidently impossible, hence there is no sūtra text [for it].