[In defining the meaning of sūtra,] Chih-i presents his own definition for the word Ching, in which Ching can bear different meanings for different people. In other words, people with different abilities take different dharmas as Ching. Chih-i’s idea is that Ching as the teaching of the Buddha is contained in all entities or dharmas. Considering that one can attain truth by any entities, any entities or dharmas can be taken as Ching.

Here, Chih-i enumerates three types of dharma that can be taken as Ching. The first type takes sound as Ching. This indicates that when the Buddha is present in the world, he orally expounds the dharma. Listeners, by hearing his voice, can attain the Path. Therefore, the Buddha’s voice is taken as Ching. The second type takes form as Ching. This means that after the Buddha entered into nirvāṇa, written records as form become the means to transmit the Buddha’s teaching. Therefore, form is taken as Ching. The third type takes the dharma as Ching. This refers to the person whose mind is united with the dharma by his own thinking. This is neither achieved by the teaching, nor by the written texts, but by the dharma.

Chih-i stresses that in human world, these three types of object as Ching can suit sentient beings with different faculties.

1. To the one, whose ear faculty is sharp, capable of attaining realization by sound, sound is the only object that can serve as Ching.
2. To the one, whose faculty of cognition is sharp, and who is capable of studying and thinking by oneself, dharma is the only object that can serve as Ching.
3. To the one, whose eye faculty is sharp, and who is capable of realizing truth through written records, form is the only object that can serve as Ching.