Valmiki Ramayana Sundara Kanda Sarga 2 Shloka 44

अत्र here, वायुरपि even wind, अज्ञातः without being detected, न चरेत् may not move, इति thus, मम my, मतिः thought, बलीयसाम् the powerful, राक्षसानाम् of demons, अविदितं unknown, किञ्चित् even a little indeed, नास्ति हि not.

'I think even the wind who has no form cannot move here without being detected. Nothing escapes the notice of powerful demons. There is nothing unknown to them.