Valmiki Ramayana Kishkindha Kanda Sarga 67 Shloka 4
Original Shlokaसंस्तूयमानो हनुमान्व्यवर्धत महाबलः। समाविध्य च लाङ्गूलं हर्षाद्बलमुपेयिवान्।।4.67.4।।
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महाबलः mighty, हनुमान् Hanuman, संस्तूयमानः being praised, हर्षात् joyfully, बलम् strength, उपेयिवान् assumed, लाङ्गूलम् tail, समाविध्य whirling, व्यवर्धत grew.
The monkeys praised the mighty Hanuman as he grew in size whirling his tail around joyfully.