Valmiki Ramayana Yuddha Kanda Sarga 25 Shloka 18

सर्वम् entire, बलम् army, दृष्टंयदि looking at the, वयम् our, सुपरिक्षिताःवा observing well, यथोक्तम् that which is appropriate, कार्यम् action, कृतंना accomplishing, छन्दतः freely, प्रतिगम्यताम् you may return back.

After observing our entire army carefully, acting appropriately (according to Ravana's words) and accomplishing your task you may freely return (said Rama to the spies).