The Harvest of the Great Nirvana (Mahaparinirvana)

“Oh, good man! For example, there is here a rich man who has only a single son. He always thinks about and loves this child. He takes the boy to a teacher to be taught. Apprehensive that things might not progress quickly, he takes the boy back home. Because he loves him, teaches him the alphabet day and night, very patiently. But it does not yet teach him the vyakarana. Why not? Because the child is small and is not able to learn such lessons. Oh, good man! However, the rich man had finished teaching the alphabet. Is the child ready to be taught the vyakarana?"

"No, Oh World Honored One!"

"Is the rich man concealing something from the child?"

"No, Oh World Honored One! Why not? Because the child is too young. Thus, it does not teach him [the more advanced matters]. It is not that the boy is not taught because the man haggles him [these lessons]. Why not? Because if there was any jealousy or envy, we could say that he conceals things. With the Tathagata is not thus. How could we say that he hides and conceals?"

The Buddha said: "Well said, well said, Oh good man! It's as you say. If there was any anger, jealousy or envy (grudgingly), we could say that he is concealing things. The Tathagata has no anger or jealousy. How could we say that he hides things? Oh, good man! The great rich man is the Tathagata himself. His only child are [all] beings. The Tathagata sees all beings as he sees his only son. (The rich man) Teaching his only child relates to the Sravaka disciples, the alphabet relates to the nine types of sutras; the vyakarana relates to the Mahayana Vaipulya [extensive] sutras. Since all the Sravaka disciples do not possess the power of Wisdom, the Tathagata teaches them the alphabet, i.e., the nine types of sutras. But it does not yet speak of the vyakarana, i.e., the Mahayana Vaipulya. Oh, good man! When the rich man's son grow and become able to cope with the lessons, if the vyakarana is not taught, then we can say that there was 'concealment'. If all Sravakas are grown up and can indeed deal with the lessons of Mahayana Vaipulya, but the Tathagata begrudges [this] and does not teach them [the vyakarana], then we could say that the Tathagata begrudges, hides and conceals the teachings. But this is not so with the Tathagata. The Tathagata does not hide [anything]. This is as with the rich man who, having taught the alphabet, next teaches the vyakarana. I also do the same. To all my disciples I have preached about the alphabet and the nine types of sutras. Having done this, I now speak about the vyakarana. This is nothing more that the eternal and unchanging nature of the Tathagata. Also, next, Oh good man! This is as in the summer months, when large clouds call forth thunderstorms, heavy rains and, as a result, all farmers can sow their seeds and harvest things. Those who do not sow cannot expect to harvest. It is not through the workings of the naga kings that one cannot harvest. And these naga kings also do not store things. The same goes with me. I let fall the great rain of the Great Nirvana Sutra. Those beings who have sown good seeds harvest the buds (shoots) and fruits of Wisdom. Those who have not sown, nothing can expect. The Tathagata is not guilty if they gain nothing. The Tathagata does not hide anything."

Read More on the Nirvana Sutra, Chapter 7 - On the Four Aspects.