स्वधर्ममपि चावेक्ष्य न विकम्पितुमर्हसि ।
धर्म्याद्धि युद्धाछ्रेयोऽन्यत्क्षत्रियस्य न विद्यते ।।
svadharmamapi cāvekṣya na vikampitumarhasi ।
dharmyāddhi yuddhāchreyo'nyatkṣatriyasya na vidyate ।।
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The highest dharma for a kshatriya is yuddha. There is nothing superior than it. This battle has already started & Oh Arjuna, it is undeserving of you to waver instead of performing your svadharma
A kshatriya can battle relatives, elders, acharyas (practically anyone) on the battlefield. The incident of bhishma himself is cited as an example
Angry at being rejected, she approached Parasurama (Bhishma's acharya) for redressal.
Acharya got impatient & ordered him to marry her. Bhishma still refused saying
'My Vow is paramount for me. It is incumbent upon me to keep it's sanctity even at the cost of disobeying my acharya'
Bhishma never hesitated because he knew it is his svadharma to battle, even if the opponent is his acharya..
Each day, till sunset both fearsome warriors would fight their hearts out. After that, Bhishma would visit his acharya's hut, attend to his wounds, pull out arrows (that he himself splayed!!), touch his feet & get blessings
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Same as (V)
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Same as (V)