Bhagavad Gita 1.40 Chapter 1, Verse 40

कुलक्षये प्रणश्यन्ति कुलधर्माः सनातनाः ।
धर्मे नष्टे कुलं कृत्स्नमधर्मोऽभिभवत्युत ॥१.४०॥

kulakṣaye praṇaśyanti kuladharmāḥ sanātanāḥ
dharme naṣṭe kulaṃ kṛtsnamadharmo'bhibhavatyuta

Meaning

When a family is destroyed, its age-old traditions perish, and when tradition is lost, lawlessness overtakes the whole family.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 1.40 (Chapter 1, Arjuna's Despair (Arjuna Vishada Yoga), Verse 40)