Valmiki Ramayana Yuddha Kanda Sarga 25 Shloka 9
Original Shlokaइतिप्रतिसमादिष्टौराक्षसौशुकसारणौ । हरिरूपधरौवीरौप्रविष्टौवानरंबलम् ।।6.25.9।।
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इति thus, प्रतिसमाधिष्टौ having accepted the order, वीरौ heroes, शुकसारणौ S uka and Saarana, राक्षसौ both Rakshasas, हरिरूपधरौ taking the form of Vanaras, वानरम् in to Vanaras, बलम् army, प्रविष्टौ entered.
Having accepted the order, both the Rakshasa heroes, Suka and Saarana took the form of Vanaras and entered the Vanara army.