大般涅槃經集解 16.96

16.96

案寶亮曰：戒如堤塘，以定慧為水。若無四依人出世令改惡從善者，則戒堤塘破壞，定慧之水盡也。

Baoliang notes: The precepts are like an embankment, with concentration and wisdom as the water. If there were no four kinds of persons of reliance appearing in the world to cause people to reform evil and follow good, the embankment of precepts would be breached and destroyed, and the water of concentration and wisdom would run completely dry.