Mbh 3.281.2

“And while Rama was on this side of the ocean, the virtuous Vibhishana, the brother of the king of the Rakshasas accompanied by four of his counsellors, came unto Rama. And the high-souled Rama received him with due welcome. Sugriva, however, feared, thinking he might be a spy. The son of Raghu, meanwhile perfectly satisfied (with Vibhishana) in consequence of the sincerity of his exertions and the many indications of his good conduct, worshipped him with respect. And he also installed Vibhishana in the sovereignty of all the Rakshasas and made him his own junior counsellor, and a friend of Lakshmana’s. And it was under Vibhishana’s guidance, O king, that Rama with all his troops crossed the great ocean by means of that bridge in course of a month. And having crossed the ocean and arrived at Lanka, Rama caused its extensive and numerous gardens to be devastated by his monkeys. And while Rama’s troops were there, two of Ravana’s counsellors and officers, named Suka and Sarana, who had come as spies, having assumed the shape of monkeys, were seized by Vibhishana. And when those wanderers of the night assumed their real Rakshasa forms, Rama showed them his troop and dismissed them quietly. And having quartered his troops in those woods that skirted the city, Rama then sent the monkey Angada with great wisdom as his envoy to Ravana.”