大通方廣懺悔滅罪莊嚴成佛經 2.27

2.27

"Good son, there are furthermore four dharmas by which one skillfully opens the giving of the Dharma. What are the four? First, guarding and preserving the true Dharma; second, benefiting one's own wisdom as well as benefiting others; third, constantly practicing the ways of good people; fourth, revealing defilement and purity, dark and bright, to others. These are named the four.