Bhagavad-gītā 2.33
BG 2.33 (1972)
Open the full passageअथ चेत्त्वमिमं धर्म्यं संग्रामं न करिष्यसि । ततः स्वधर्मं कीर्तिं च हित्वा पापमवाप्स्यसि ॥३३॥
Sanskrit
atha cet tvam imaṁ dharmyaṁ saṅgrāmaṁ na kariṣyasi tataḥ sva-dharmaṁ kīrtiṁ ca hitvā pāpam avāpsyasi
Translation
If, however, you do not fight this religious war, then you will certainly incur sins for neglecting your duties and thus lose your reputation as a fighter.