Bhagavad Gita 1.42

सङ्करो नरकायैव कुलघ्नानां कुलस्य च।पतन्ति पितरो ह्येषां लुप्तपिण्डोदकक्रियाः॥

saṅkaro narakāyaiva kulaghnānāṃ kulasya ca |patanti pitaro hyeṣāṃ luptapiṇḍodakakriyāḥ ||

Confusion of castes leads to hell for the slayers of the family, for their forebears fall, deprived of the offerings of rice-balls and libations of water.

Promiscuity ruins both the family and those who defile it; while the souls of our ancestors droop, due to the lack of funeral cakes and ablutions.

Our plain-language meaning of this verse is waiting for scholar review.