Valmiki Ramayana Yuddha Kanda Sarga 59 Shloka 135
Original Shlokaराक्षसेनाहवेतस्यताडितस्यापिसायकैः । स्वभावतेजोयुक्तस्यभूयस्तेजोऽभ्यवर्धत ।।6.59.135।।
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राक्षसेन by the Rakshasa, आहवे discharged, सायकैः arrows, ताडितस्यापि when hurt him also, स्वभावतेजोयुक्तस्य by nature endowed with energy, तस्य his, तेजः energy, भूयः exceedingly, अभ्यवर्धत went on increasing.
Even though Hanuman was hurt by the arrows discharged by the Rakshasa king, being endowed with energy by nature, his energy went on increasing.