宋高僧傳 3.43

3.43

Fourth, coarse speech and fine speech: within linguistic science (śabdavidyā), the first is subanta, referring to ordinary, colloquial speech and expressions. The second is tiṅanta, referring to classical, correct speech and expressions. The Buddha's preaching of the Dharma mostly relied upon subanta, his intention abiding in the meaning and not relying on the letter, and also because it addressed everyone; whereas tiṅanta could not be understood by all kinds of beings. Therefore, what is also called 'full sound' is when the pronunciation is distinct, classical, and correct; this is fine speech. 'Half sound' is when the pronunciation is indistinct and corrupted or vernacular; this is coarse speech.