大般涅槃經集解 29.8

29.8

案僧亮曰：捨生名死，譬門外也。反生易顯，不須辭費也。即持利刀者，醫藥救生，譬持利刀，以防死也。僧宗曰：死是人之所惡，悲情內故，譬之門外也。

Sengliang comments: Relinquishing birth is called death, compared to being outside the gate. Being the opposite of birth, it is easy to manifest, requiring no lavish explanation. The one who immediately took a sharp knife: medicine rescues life, compared to holding a sharp knife to guard against death. Sengzong comments: Death is what humans hate; since sorrowful sentiments are kept within, it is compared to being outside the gate.