大般涅槃經集解 8.80

8.80

案僧宗曰：向問多頭，是諮身密；今問說法，是諮口密。根有利鈍、教有淺深，月一日至十五日也。寶亮曰：明佛如父母，不欺於子，隨根性而說法，以勸信也。

Sengzong states: The preceding question about the many heads inquired into the mystery of the body; now this question about preaching the Dharma inquires into the mystery of speech. Faculties may be sharp or dull, and teachings may be shallow or deep, just as [the moon waxes from] the first to the fifteenth day. Baoliang states: This clarifies that the Buddha is like a parent who does not deceive his children, preaching the Dharma in accordance with their faculties and dispositions to encourage faith.