Bhagavad Gita - Chapter 1 - Shloka (Verse) 43

दोषैरेतैः कुलघ्नानां वर्णसङ्करकारकैः।
उत्साद्यन्ते जातिधर्माः कुलधर्माश्च शाश्वताः।।1.43।।
doṣairetaiḥ kulaghnānāṃ varṇasaṅkarakārakaiḥ|
utsādyante jātidharmāḥ kuladharmāśca śāśvatāḥ||1.43||
Translation
By these evil deeds of the destroyers of the family, which
cause confusion of castes, the eternal religious rites of the caste and
the family are destroyed.
हिंदी अनुवाद
इन वर्णसंकर पैदा करनेवाले दोषोंसे कुलघातियों के सदा से चलते आये कुलधर्म और जातिधर्म नष्ट हो जाते हैं।
Commentaries & Translations
Swami Ramsukhdas
व्याख्या--'दोषैरेतैः कुलघ्नानाम् ৷৷. कुलधर्माश्च शाश्वताः'--युद्धमें कुलका क्षय होनेसे कुलके साथ चलते आये कुलधर्मोंका भी नाश हो जाता है। कुलधर्मोंके नाशके कुलमें अधर्मकी वृद्धि हो जाती है। अधर्मकी वृद्धिसे स्त्रियाँ दूषित हो जाती हैं। स्त्रियोंके दूषित होनेसे वर्णसंकर पैदा हो जाते हैं। इस तरह इन वर्णसंकर पैदा करनेवाले दोषोंसे कुलका नाश करनेवालोंके जातिधर्म (वर्णधर्म) नष्ट हो जाते हैं।
Sri Anandgiri
Moreover, when caste duties and family duties are destroyed, falling into hell is certain for men who are devoid of those respective duties and have lost their eligibility. Therefore, this evil-producing (war) must be abandoned; this he states with "utsanna" (destroyed) etc.
He cites authority regarding the inevitability of the fall into hell for such described men with "iti anuśuśruma" (thus we have heard).
Sri Dhanpati
By these stated faults of the family destroyers—which are the causes of the intermixture of castes—
the duties applicable to caste and the duties applicable to family, all of which are eternal and ancient, are completely eradicated; that is, they are made extinct or destroyed.
Sri Neelkanth
He elaborates on this very point through two verses
beginning with "doṣaiḥ" (by these faults).
Sri Ramanuja
Sanjaya said: That Partha (Arjuna)—who is high-minded, supremely compassionate, possessed of extensive kinship ties, supremely righteous, and accompanied by his brothers; although repeatedly deceived by you (Kauravas) through terrible, murderous means such as the house of lacquer, and despite having the Supreme Person as his ally—
upon beholding your people about to be killed, and with his entire body perspiring excessively due to affection for kinsmen, supreme pity, and fear of righteousness and unrighteousness,
said "I will not fight at all." Then, with a mind agitated by the grief born of separation from his kinsmen, he cast aside his bow and arrows and sat down on the seat of the chariot.
Swami Chinmayananda
पूर्व श्लोक की टीका का अर्थ अर्जुन के इस वाक्य से और अधिक स्पष्ट हो जाता है। जैसा कि हमने देखा धर्म का अर्थ है भारतीय आध्यात्मिक संस्कृति जिसका प्रशिक्षण प्रत्येक घर में ही प्रारम्भ से मिलता था। अर्जुन का यह भय कि इस गृहयुद्ध से जातिधर्म व कुलधर्म नष्ट हो जायेंगे सामान्य ज्ञान की बात है। यह सुविदित है कि प्रत्येक युद्ध के बाद समाज में नैतिक और सांस्कृतिक मूल्यों का सहसा कितना पतन होने लगता है। अनैतिकता और छलकपट की प्रवृत्तियों के नीचे दबा हाँफ रहा आज का युग उपरोक्त तथ्य का ज्वलंत उदाहरण है। युद्ध के बाद न केवल लंगड़े लूलों की संख्या बढ़ती है वरन् उससे भी भयंकर परिणाम मन की गंभीर विकृतियों के रूप में सामने आते हैं।इन श्लोकों में हम अर्जुन को संसार के सर्वप्रथम युद्धविरोधी व्यक्ति के रूप में पाते हैं। इन अनुच्छेदों में वह शान्ति प्रिय लोगों के लिये सार्वकालिक तर्कों की एक सुन्दर शृंखला भेंट करता है।
Sri Abhinavgupta
Nihatya" (Having killed) etc. In the act of killing aggressors (ātatāyins), sin itself is the agent. Therefore, the meaning is this: these enemies of ours have already been killed (or enslaved) by sin. And by killing them, sin would take shelter in us as well.
Here, 'sin' refers to the failure to perceive the faults like the destruction of the family due to the influence of greed and so forth.
That is precisely why he introduces the topic of family duties (kuladharma) with the words "svajanaṃ hi katham" (how indeed [can we kill] our own people) and so on.
Sri Madhusudan Saraswati
And consequently, due to the absence of the cause (rites) to reverse the state of being a departed spirit (pretatva), residence takes place solely and continuously in hell. "Inevitably" (dhruvam)—"thus we have heard" (iti anuśuśruma)—meaning we have heard this from the mouths of the teachers, and we do not fabricate this by our own conjecture.
This is a confirmation of what was stated previously.
Sri Purushottamji
Moreover, hell indeed befalls the destroyers of the family—what need is there to speak of it? For, due to connection with them, the destruction of righteousness (dharma) occurs everywhere on earth; this he states with "doṣairetaiḥ" (by these faults).
By these faults which cause the intermixture of castes—by these faults of the family destroyers—the eternal duties of the caste (jātidharmāḥ) and duties of the family (kuladharmāḥ) are uprooted; meaning they are obliterated.
By the particle "cha" (and), the duties of the stages of life (āśrama-dharma) etc., are also included.
Swami Adidevananda
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.