2:31  

स्वधर्ममपि चावेक्ष्य न विकम्पितुमर्हसि ।
धर्म्याद्धि युद्धाच्छ्रेयोऽन्यत्क्षत्रियस्य न विद्यते ॥२- ३१॥

swadharmamapi chaawekShya na wikampitumarhasi ।

dharmyaaddhi yuddhaachChreyo'nyatkShatriyasya na widyate ॥२- ३१॥

Source: Automatic ITRANS Transliteration

Considering your personal duty, it is inappropriate for you to balk.
For a Kshatriya, other than fighting a righteous war, no success is known.

Source: Milind S. Pandit

Considering also your duty as a warrior you should not waver. Because there is nothing more auspicious for a warrior than a righteous war.

Source: The Bhagavad-Gita: The Sacred Song

Considering your specific duty as a ksatriya, you should know that there is no better engagement for you than fighting on religious principles; and so there is no need for hesitation.

Source: Bhagavad Gita As It Is