Valmiki Ramayana Ayodhya Kanda Sarga 51 Shloka 1

गुहः Guha, भ्रातुः brother, अर्थाय for the sake of, जाग्रतम् keeping awake, राघवम् Raghava born in the family of the Raghus, तं लक्ष्मणम् to that Lakshmana, अदम्भेन without any pretence, सन्तापसन्तप्तः tormented with grief, वाक्यम् these words, अब्रवीत् said.

Deeply moved to see Lakshmana, scion of the Raghus, keeping awake all night without any pretence for his brother's sake, Guha spoke. Lakshmana tells Guha about events which might overtake Ayodhya after Rama's exile