大般涅槃經集解 23.36

23.36

案僧亮曰：如來教法先淺後深，唯涅槃究竟，無惑不除也。寶亮曰：第十二譬，與《法華》之前經作喻也。除三毒并等分，及四倒故，故言八術。復能博達過八種者，譬涅槃經教有十二術也。此兩譬所以就人為喻者，遣物疑也。

Sengliang comments: The Tathāgata's teaching is shallow first and deep later; only the Nirvāṇa is definitive, with no delusion left uneradicated. Baoliang comments: The twelfth parable serves as an illustration alongside the sūtras prior to the Saddharmapuṇḍarīka Sūtra. Because it eliminates the three poisons together with their equal combinations, and the four inversions, it speaks of 'eight arts'. Being extensively knowledgeable beyond the eight kinds is likened to the Nirvāṇa Sūtra's teaching having twelve arts. The reason these two parables take persons as illustrations is to dispel doubts among beings.