Valmiki Ramayana Sundara Kanda Sarga 2 Shloka 43
Original Shlokaन हि शक्यं क्वचित् स्थातुमविज्ञातेन राक्षसैः। अपि राक्षसरूपेण किमुतान्येन केनचित्।।5.2.43।।
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राक्षसैः by demons, अविज्ञातेन without being identified, राक्षसरूपेणापि even by assuming the form of a demon, क्वचित् anywhere, स्थातुम् to stay with them, न शक्यं हि not be possible, अन्येन in other form, केनचित् by any form, किमुत what to say.
'It is difficult to stay with the demon anywhere here even in the disguise of a demon without being identified. It will not be possible to remain unidentified even by assuming any other form.