維摩經玄疏 2.38

2.38

The reason these three are collectively called 'contemplations' is that 'contemplation' (guan) has the meaning of 'piercing through' (guanchuan) and also has the function of 'thoroughly penetrating' (guanda). 'Piercing through' means piercing through the delusions of views and thoughts, of [delusions as numerous as] the Ganges sands, and of fundamental ignorance; hence it is called 'piercing through'. 'Thoroughly penetrating' means thoroughly penetrating the principle of the three truths. Therefore the Mahāparinirvāṇa Sūtra says: 'Just like a person who well knows where a hidden treasure lies: he immediately takes a sharp hoe and digs straight down into the earth; boulders, sand, and gravel are passed straight through without difficulty; only when he reaches vajra can he pierce no further.' 'Boulders' are the delusions of views and thoughts. 'Sand' is the delusion of nescience [as numerous as] fine particles of dust and sand. 'Gravel' is the delusion of the entrenched ground of fundamental ignorance. 'Passing through' is precisely the meaning of piercing through. 'Reaching vajra' is thoroughly penetrating the principle of the one real truth, the buddha-nature.