大般涅槃經集解 20.52

20.52

案僧亮曰：廣以事證耳。寶亮曰：名肥膩者，此為行人作譬也。雪山喻五陰身，草譬因果性六行理也，牛譬行人。若於涅槃因果佛性中學，直向佛果，不經四趣。

Sengliang states: This is merely an extensive verification by means of concrete facts. Baoliang states: That which is called 'rich and fertile' is a metaphor made for the practitioner. The Snow Mountains symbolize the body of the five aggregates; the grass symbolizes the principle of the six practices regarding the nature of cause and effect; the cow symbolizes the practitioner. If one trains in nirvāṇa's cause-and-effect buddhadhātu, one heads straight toward the fruit of buddhahood and does not pass through the four destinies.