Valmiki Ramayana Kishkindha Kanda Sarga 3 Shloka 1

हनुमान् Hanuman, महात्मनः great self, सुग्रीवस्य Sugriva's, वचः words, विज्ञाय listening, ऋष्यमूकात् पर्वतात् from mountain Rishyamuka, राघवौ both (Rama and Lakshmana), यत्र where, पुप्लुवे leapt

Listening to great Sugriva, Hanuman leaped from mount Rishyamuka on to the location of the Raghavas. Hanuman goes in the guise of a pious mendicant to meet Rama and Lakshmana -- Rama wonders at Hanuman's knowledge -- Hanuman reveals his identity and the purpose of his meeting -- Rama agrees to see Sugriva