Bhagavad Gita 1.44

The wise say, my Lord, that they are forever lost whose ancient traditions have been lost.

उत्सन्नकुलधर्माणां मनुष्याणां जनार्दन।
नरकेऽनियतं वासो भवतीत्यनुशुश्रुम॥

utsannakuladharmāṇāṃ manuṣyāṇāṃ janārdana|
narake'niyataṃ vāso bhavatītyanuśuśruma||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).