Sachi, the wife of Indra, is considered to be a form of Lakshmi. She is the goddess of fortune. It is said that any one can become an Indra by earning more merit than the previous Indra. On becoming an Indra, one has access to Sachi. Sachi is faithful to the rank of Indra, not to the person who is Indra. Nahusha is not yet Indra; he is a temporary replacement, a lesser being. Though not worthy, he dares desire Sachi and thus pays for it. The tale is less about morality (do not desire the wife of another man) and more about prudence (do not aspire for things until you are worthy).
