Bhagwad Gita
Chapter 2, Verse 31
स्वधर्ममपि चावेक्ष्य न विकम्पितुमर्हसि।
धर्म्याद्धि युद्धाछ्रेयोऽन्यत्क्षत्रियस्य न विद्यते।।2.31।।
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.