大方廣佛華嚴經疏 1.17

1.17

Ninth, opening up the causal nature: the causes, fruits, noumenon, and phenomena above are all possessed by the nature of sentient beings. If the nature is not gold or jade, though carved, it will not become a precious vessel. For indeed, sentient beings take the virtue of the nature as their essence and rely on the ocean of wisdom as their source; yet marks shift and essences seem distinct, emotion arises and wisdom is estranged. Now, to let them know that the mind accords with the essence and to realize the source so that emotion vanishes, this sūtra is spoken to reveal it. This also has two kinds: first, revealing it through words to let them know it exists; second, causing them to cultivate and realize it so that it becomes manifest, like cracking the paramāṇu to bring forth the sūtra scroll below, and so forth. It is also as the Saddharmapuṇḍarīka says: 'It is only for the causes and conditions of one great matter that they appear in the world, namely to open, reveal, awaken to, and enter the vision and knowledge of the Buddha.' Because sentient beings possess it equally, it is said to be 'only one.'