大般涅槃經義記 7.173

7.173

下次合之，先合初喻，「菩薩」合前惶怖之人，「得聞涅槃」合聞切令，「觀身如篋」合下四蛇，地、水、火、風如四毒蛇舉以略合。

Next is the application. First is the application of the first analogy: 'the bodhisattva' corresponds to the frightened person before; 'hearing the nirvāṇa' corresponds to hearing the urgent command; 'contemplating the body like a casket' corresponds to the four snakes below; earth, water, fire, and wind being like four poisonous snakes is adduced as a brief application.