Vishnupurana 3.18.p15

3.18.p15

These are the persons, O Maitreya, called naked, the meaning of which term you wanted me to explain. If they witness a Srāddha ceremony that becomes fruitless—communication with whom spoils the piety of one day. These are the heretics with whom the wise should not converse—and speaking to whom destroys the virtue he might have obtained that day. Men fall into hell if they converse with them who uselessly assume the twisted hair and shaven head, who eat without offering food to gods, spirits and guest and those who do not offer cakes and libation of water to their manes.