Valmiki Ramayana Kishkindha Kanda Sarga 2 Shloka 24
Original Shlokaतौ त्वया प्राकृतेनैव गत्वा ज्ञेयौ प्लवङ्गम। इङ्गितानां प्रकारैश्च रूपव्याभाषणेन च4.2.24।।
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प्लवङ्गम O Monkey, त्वया by you, प्राकृतेनैव by assuming an ordinary form, गत्वा going, तौ the two, इङ्गितानाम् their gestures, प्रकारैश्च by their traits, रूपव्याभाषणेन by their form and conversation, ज्ञेयौ should be found out
'O Hanuman assume an ordinary form and approach them. Try to read them through their gestures, traits, forms and conversations.