金光明最勝王經疏 2.211

2.211

贊曰：明大淨德。外道不信涅槃淨德，妄計餘淨能得涅槃之真淨德，如鷦鷯鳥不能銜香山遊。香山，喻大涅槃淨德。鳥，喻外道。不信佛說，依自見行謂得真淨，決定不得。既真法身不無常苦、無我不淨，明知舍利決不可得。故求舍利依供養故，為安樂因成本願者，必不可得。故應觀佛離三相、成三德，除四障、修四因，定得願滿。

The commentary states: This clarifies the virtue of great purity. Non-Buddhists do not believe in the pure virtue of nirvāṇa, and falsely calculate that other purities can attain the true pure virtue of nirvāṇa, just as a tiny wren cannot hold Mount Gandhamādana in its beak and roam. Mount Gandhamādana exemplifies the pure virtue of great nirvāṇa. The bird exemplifies non-Buddhists. Not believing what the Buddha preached and acting in accordance with their own views, they claim to attain true purity, but definitely cannot attain it. Since the true dharmakāya is not impermanent, suffering, non-self, or impure, it is clearly understood that relics can definitely not be obtained. Therefore, seeking relics on the basis of making offerings as the cause of peace and bliss to fulfill one's original vow is something that can never be obtained. Hence one should contemplate the Buddha as free from the three marks and perfected in the three virtues, eliminating the four obstacles and cultivating the four causes; then one will surely have one's vows fulfilled.