Why Did the Past Patriarchs and Great Masters Generally Not Cite Scriptures and Classics When Expounding the Dharma

Question: Why did the patriarchs and great masters of the past generally not cite scriptures when expounding the Dharma? 

Answer: The patriarchs and great masters of the past were genuinely awakened bodhisattvas with true cultivation, true realization, and true virtuous conduct. Therefore, when expounding the Dharma, they spoke only from their own wisdom and insight, without seeking exhaustive elaboration and without concealment—speaking truthfully and reasoning in accordance with the Dharma. If they occasionally cited scriptures, it was either for those whose conditions were not yet ripe and whose faculty of faith and wisdom were insufficient, or, when the Dharma-meaning was profound, to use the Buddhist sūtras as supplementary illustration. 

From another perspective, in ancient times practitioners had relatively deep roots of goodness, with excellent merit, meditative concentration, and wisdom, sufficient faculty of faith, and the eye for discerning the Dharma; they had the correct power of discernment and the capacity of faith to receive the patriarchs' teachings. Thus, when the patriarch-bodhisattvas expounded the Dharma, they could confidently speak of what their wisdom and realization knew, without any misgivings. Sentient beings today have only slight and scant roots of goodness, lacking merit, meditative concentration, and wisdom, with insufficient faculty of faith and lacking the eye for discerning the Dharma; many people would rather be deceived than take good advice. Therefore, when expounding the Dharma, one must cite many scriptures to inspire faith. On the other hand, if the Dharma teacher has cultivated for only a short period of kalpas, without genuine wisdom and realization, and has not yet penetrated the Dharma-meaning, then he has no choice but to cite scriptures. Yet even when citing scriptures, first, sentient beings cannot understand them as they truly are, and second, the Dharma teacher himself has not thoroughly mastered the sūtras, so misunderstanding and misinterpretation are still unavoidable. This is the result of sentient beings' karmic power: with heavy karma and meager merit, the path of cultivation becomes winding and tortuous, advancing and retreating, with no knowing when it will ever come to an end.