The envoy in his faithful breast Pondered Sugríva’s high behest. From Rishyamúka’s peak he hied And placed him by the princes’ side. The Wind-God’s son with cautious art Had laid his Vánar form apart, And wore, to cheat the strangers eyes, A wandering mendicant’s disguise.

In plain words: Hanuman, son of the Wind-God and a messenger for the monkey king Sugriva, goes down from Rishyamuka mountain to meet Rama and Lakshmana. To be careful, he hides his monkey form and disguises himself as a wandering beggar-monk.