अष्टा दशपुरणानम सारं व्यासेन कीर्थितम |
परोपकारः पुण्याय पपाया परपीडनम |

Astadashapuranaanam saaram vyasena keerthitam
paropakaraha punyaya, paapaya parapeeditam

In all the eighteen puranas, sage vyasa emphasizes ony two moral precepts
Rendering service to people is merit and harassing them is evil