ANG 1015 of Sri Dasam Granth Ji:
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If I fall as a martyr while fighting with my enemies (tyrants) then I shall think that I have realized Truth; O Sustainer of the Universe ! May I always help the saints in this world and destroy the tyrants; bestow this boon on me.
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may I not fear the enemy, when I go to fight and assuredly with thy grace I gain victory.
may I give this instruction to my mind and have temptation that I ever utter Thy Praises.
When the end of my life comes, May I die fighting in the battlefield.
From Ang 1412 of Sri Guru Granth Sahib Ji Maharaj: