Canto 3 -
Araṇya-kāṇḍa
Chapter 11: Rāma Goes to Agastya’s Āśrama
Text 3.11.19

तथैवाप्सरसः पञ्च निवसन्त्यो यथासुखम्।
रमयन्ति तपोयोगान्मुनिं यौवनमास्थितम्॥

tathaivāpsarasaḥ pañca nivasantyo yathā-sukham
ramayanti tapo-yogān muniṁ yauvanam āsthitam

tathā eva = thus; apsarasaḥ = apsarās; pañca = the five; nivasantyaḥ = residing; yathā-sukham = happily; ramayanti = delight; tapaḥ-yogāt = by dint of his austerities 5; munim = the sage; yauvanam āsthitam = who has achieved youth.

Happily residing thus, the five apsarās delight the sage who has achieved youth by dint of his austerities.