The all-embracing feature of the mind contemplation is revealed by the unity of the three categories of Dharma in the quotation from the Avatamsakasūtra:

“The mind, Buddha, and sentient beings are of no distinction.”

Chih-i points out that what mind contemplation can achieve is described by yet another quote from the Avatamsakasūtra:

“When one’s mind traverses the Dharma-realm, taking it as if it is empty space, then one will know the objective realm of all Buddhas.”

Chih-i believes that this quotation, in terms of the mind traversing the Dharma-realm, suggests that mind is related to the Threefold Truth, and that contemplating the mind is the means to attain the Threefold Truth. Chih-i explains:

“The Dharma-realm is identical to the Middle Way. Empty space is identical to Emptiness. The mind and Buddhas are identical to the Provisional. The three together are identical to the objective realm of all Buddhas. This means that if one contemplates [the thought of] one’s mind, one can still be endowed with all the Buddha-dharmas.”

The all-embracing feature of the mind is further emphasized by Chih-i as he holds that contemplating the mind is about one thought embracing reality as a whole:

“In the case of one’s mind traversing the Dharma-realm, when contemplating the mutual opposition of a sensation and its object, one thought arises in the mind which must belong to one of the ten realms. When [one thought] belongs to one realm, it at once embraces one hundred realms and one thousand dharmas. The one thought is replete with all [aspects of reality].”

This passage addresses that all characteristics of reality are contained in the rising of one thought. Therefore, contemplating the mind is the most practical method in reaching truth. (Vol. 2, Page 81-82)