Canto 3 -
Araṇya-kāṇḍa
Chapter 11: Rāma Goes to Agastya’s Āśrama
Text 3.11.35

मनोरथो महानेष हृदि मे परिवर्तते।
यदहं तं मुनिवरं शुश्रूषेयमपि स्वयम्॥

manoratho mahān eṣa hṛdi me parivartate
yad ahaṁ taṁ muni-varaṁ śuśrūṣeyam api svayam

manorathaḥ = desire; mahān = great; eṣaḥ = this; hṛdi = in heart; me = My; parivartate yat = is present; aham = I; tam = the; muni-varam = excellent sage; śuśrūṣeyam = would like to serve; api svayam = personally.

This great desire is present in My heart: I would like to personally serve the excellent sage.