The Parable of the Good Son

“Also, next, oh good man! This is like the doctor who makes efforts and imparts basic medical knowledge to his son, saying that this is the root medicine, this for taste, that's for color etc.., thus allowing to his son become familiar with the various properties [of medicines]. The son pays heed to what his father says, makes efforts, learns and comes to understand all the [different] types of medicines. There comes a time when his father dies. The son yearns, weeps and says: 'father taught me by saying that this is the root medicine, this is of the stem, this is the flower and this for color’. The same goes with the Tathagata. In order to guide us, he imposes many restrictions to beings. Thus, we should try to act in accordance with [those restrictions] and not antagonize them. For those people of the five deadly sins, for those slanderers of the Wonderful Dharma, for the icchantikas, and for those who might commit such deeds (slanderous) in the days to come, he manifests himself accordingly. All this is for the days after the death of the Buddha, for the bhiksus to know that these are important points in the sutras, these are the heavy and light aspects of the precepts, these are the passages of the Abhidharma which are important (weighty ) or not important. This is to enable them to be like the son of the doctor.”

Read More on the Nirvana Sutra, Chapter 15 - On the Parable of the Moon.