kula-kṣaye praṇaśyanti
kula-dharmāḥ sanātanāḥ
dharme naṣṭe kulaḿ kṛtsnam
adharmo ‘bhibhavaty uta

Translation of Bhagavad Gita 1.39

With the destruction of dynasty, the eternal family tradition is vanquished, and thus the rest of the family becomes involved in irreligion.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

In the system of the varnashrama institution there are many principles of religious traditions to help members of the family grow properly and attain spiritual values. The elder members are responsible for such purifying processes in the family, beginning from birth to death. But on the death of the elder members, such family traditions of purification may stop, and the remaining younger family members may develop irreligious habits and thereby lose their chance for spiritual salvation. Therefore, for no purpose should the elder members of the family be slain.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

The right conduct maintained by the family which has passed down from many generations (sanatanah kula dharmah) will be destroyed with the destruction of the family (kula ksaye).

Commentary by Sri Ramanuja of Sri Sampradaya:

1.26 – 1.47 Arjuna said — Sanjaya said — Sanjaya continued: The high-minded Arjuna, extremely kind, deeply friendly, and supremely righteous, having brothers like himself, though repeatedly deceived by the treacherous attempts of your people like burning in the lac-house etc., and therefore fit to be killed by him with the help of the Supreme Person, nevertheless said, ‘I will not fight.’ He felt weak, overcome as he was by his love and extreme compassion for his relatives. He was also filled with fear, not knowing what was righteous and what unrighteous. His mind was tortured by grief, because of the thought of future separation from his relations. So he threw away his bow and arrow and sat on the chariot as if to fast to death.

The Supreme Lord Krishna, Hrsikesa, the master of the senses. The Supreme Controller, internally and externally of all living entities evolving and evolved. Who although the Supreme Lord of all, yet descended down to Earth out of His causeless mercy for the redemption of the faithful and even more, He condescended to be Arjuna’s chariot driver, carrying out his wish to station their chariot in such a commanding position as to be able to readily view the belligerent Kauravas and put within the range of his vision such heroes as Bhishmadeva, Dronacarya and Kripa and the Kings of royal dynasties. At that time the Supreme Lord Krishna said to Arjuna: see what chances there are for the Kauravas victory over thee.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

When the spiritual traditions and spiritual values are destroyed in society, unrighteousness predominates and the surviving family members become degraded.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Sri Madhvacharya did not comment on this sloka.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Some may ponder just what sin is Arjuna describing and this is now revealed in this verse. In a dynasty it is the father that is the foundation of the family. He insures that the tradition of the members is maintained as well being the support of all the members. In times of war it is the father who goes to fight and sometimes the older sons who are the fathers of the future also go to war. If they are slain in battle it is understood that the family is effectively destroyed and righteousness along with the age- old family customs and Vedic traditions eventually cease to exist. The women and children not being properly protected, having lost the shelter of the father are thus overcome by the realities of basic survival and become victims of unrighteousness.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

1.39 Sri Sankaracharya did not comment on this sloka. The commentary starts from 2.10.

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

1.35 1.44 Nihatya etc. upto anususruma. Sin alone is the agent in the act of slaying these desperadoes. Therefore here the idea is this : These ememies of ours have been slain, i.e., have been take possession of, by sin. Sin would come to us also after slaying them. Sin in this context is the disregard, on account of greed etc., to the injurious consequences like the ruination of the family and the like. That is why Arjuna makes a specific mention of the [ruin of the] family etc., and of its duties in the passage ‘How by slaying my own kinsmen etc’. The act of slaying, undertaken with an individualizing idea about its result, and with a particularizing idea about the person to be slain, is a great sin. To say this very thing precisely and to indicate the intensity of his own agony, Arjuna says only to himself [see next sloka]:

Sanskrit Shloka Without Transliteration Marks:

kula-ksaye pranasyanti
kula-dharmah sanatanah
dharme naste kulam krtsnam
adharmo ‘bhibhavaty uta

Sanskrit to English Word for Word Meanings:

kula-kṣaye — in destroying the family; praṇaśyanti — become vanquished; kula-dharmāḥ — the family traditions; sanātanāḥ — eternal; dharme — religion; naṣṭe — being destroyed; kulam — family; kṛtsnam — whole; adharmaḥ — irreligion; abhibhavati — transforms; uta — it is said.