1.40

कुलक्षये प्रणश्यन्ति कुलधर्माः सनातनाः ।
धर्मे नष्टे कुलं कृत्स्नमधर्मोऽभिभवत्युत ॥

kulakṣaye praṇaśyanti kuladharmāḥ sanātanāḥ
dharme naṣṭe kulaṃ kṛtsnam adharmo 'bhibhavaty uta

He starts the cascade. Family destroyed, then dharma, then the whole house.

The verse

When a family is destroyed, its ancient dharmas perish. When dharma perishes, lawlessness overcomes the whole family.

नेपालीमा

कुल नाश हुँदा त्यसका पुराना धर्महरू नाश हुन्छन्। धर्म नाश हुँदा अधर्मले सारा कुललाई जित्छ।

Where it sits

dharma (धर्म) was the first word of the book, inside dharmakṣetre (धर्मक्षेत्रे). Arjuna now uses it as a house-law that dies with the men who practice it. He is predicting a social collapse, not yet talking about the self. The cascade he builds through 1.44 — family, dharma, women, mixed birth, ancestors, hell — is one argument. Learn it as a chain, then notice, when chapter 2 begins, that Kṛṣṇa (कृष्ण) does not pick the chain apart link by link.

Split: कुल-क्षये + प्रणश्यन्ति + कुल-धर्माः + सनातनाः + धर्मे + नष्टे + कुलम् + कृत्स्नम् + अधर्मः + अभिभवति + उत

kula-kṣaye + praṇaśyanti + kula-dharmāḥ + sanātanāḥ + dharme + naṣṭe + kulam + kṛtsnam + adharmaḥ + abhibhavati + uta

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
कुल-क्षयेkula-kṣayelocativewhen the family is destroyed. In the destruction of the family.
प्रणश्यन्तिpraṇaśyantipresent, 3rd pluralthey perish, they vanish.
कुल-धर्माःkula-dharmāḥnominative pluralthe dharmas of the family. The rites and duties that belong to a house.
सनातनाःsanātanāḥnominative pluralancient, perpetual.
धर्मेdharmelocativewhen dharma is…
नष्टेnaṣṭelocativedestroyed. Agrees with dharme (धर्मे).
कुलम्kulamnominativethe family.
कृत्स्नम्kṛtsnamnominative, neuterthe whole.
अधर्मःadharmaḥnominativethe absence of dharma, lawlessness.
अभिभवतिabhibhavatipresent, 3rd singularit overcomes.
उतutaindeclinableand, indeed. It leans on the last claim.

The phrases

kulakṣaye praṇaśyanti kuladharmāḥ sanātanāḥ (कुलक्षये प्रणश्यन्ति कुलधर्माः सनातनाः) is the first step. When a family is destroyed, its ancient dharmas perish. kulakṣaye (कुलक्षये) can be read as a plain locative, "in the destruction," and the force is "when."

dharme naṣṭe (धर्मे नष्टे) is a locative absolute. When dharma has been destroyed.

कुलं कृत्स्नम् अधर्मः अभिभवति kulaṃ kṛtsnam adharmaḥ abhibhavati is what follows. Lawlessness overcomes the whole family. अधर्मः + अ adharmaḥ + a becomes adharmo 'bhibhavati (अधर्मो ऽभिभवति).

uta (उत) at the end adds weight to the overcoming, a spoken "and that is not all," pointing forward to 1.41.

Sanskrit in this line

A locative absolute is a noun and a participle, both locative, meaning "when this has happened." dharme naṣṭe (धर्मे नष्टे), "dharma having been destroyed." You met one in 1.14, the chariot yoked, and one in 1.20, the weapons clashing. This one is conditional and grim. The shape is the same. The participle naṣṭe (नष्टे) is what makes dharme (धर्मे) a time, not only a location.

sanātana (सनातन) is "ancient" in the sense of "what has always been the duty," not "old-fashioned." kuladharmāḥ sanātanāḥ (कुलधर्माः सनातनाः) are the standing obligations of a house. He thinks they die if the house's men die.

Say it back

Two steps. What perishes when the family perishes, and what overcomes the family when that perishes. Say dharme naṣṭe (धर्मे नष्टे) as a when-clause.