大般涅槃經集解 51.6

51.6

案僧亮曰：此三譬通為四法近涅槃作譬也。僧宗曰：就此歎中有兩翻，前總歎、後別歎也。總歎有四重。此即第一舉四譬，先顯善知識之德也。

Sengliang comments: These three similes generally serve as similes for the four dharmas being proximate to nirvāṇa. Sengzong says: Within this praise there are two rounds: first general praise, and later specific praise. The general praise has four layers. This is the first, presenting four similes to first reveal the virtues of a good friend.