Know, godlike youths, that I am one Of his chief lords, the Wind-God’s son. With course unchecked I roam at will, And now from Rishyamúka’s hill, To please his heart, his hope to speed, I came disguised in beggar’s weed.”

In plain words: Hanuman says he is one of Sugriva's chief helpers and the son of the Wind-God. He can travel anywhere freely, and he came from Rishyamuka hill dressed as a beggar to help his king's hopes.