Shloka 51
तथैव दुर्गसंस्कारं देवैरपि दुरासदम् । स्त्रियोडपि यस्यां युध्येयु: किमु वृष्णिमहारथा:,हमने कुशस्थली दुर्गकी ऐसी मरम्मत करायी कि देवताओंके लिये भी उसमें प्रवेश करना कठिन हो गया। अब तो उस दुर्गमें रहकर स्त्रियाँ भी युद्ध कर सकती हैं, फिर वृष्णिकुलके महारथियोंकी तो बात ही क्या है?
tathaiva durgasaṃskāraṃ devair api durāsadam | striyo 'pi yasyāṃ yudhyeyuḥ kimu vṛṣṇimahārathāḥ ||
同样地，我已将俱沙斯他利（Kuśasthalī）的堡垒加固整修得极其坚固，纵使诸天也难以攻破。如今在那要塞之内，连妇女都能有效作战——更何况毗湿尼（Vṛṣṇi）族的诸位大车战士，又何须多言？
श्रीकृष्ण उवाच
Educational Q&A
The verse underscores prudent preparedness and deterrence: strengthening defenses makes even unlikely defenders effective, and therefore trained heroes become overwhelmingly capable. Ethically, it reflects a kṣatriya ideal of safeguarding one’s people through foresight and strategic security.
Kṛṣṇa speaks about having Kuśasthalī fortified so strongly that it would be difficult even for divine forces to breach. He uses this to emphasize the formidable security of the stronghold and, by extension, the fighting capacity of the Vṛṣṇi warriors who would defend it.