Valmiki Ramayana Ayodhya Kanda Sarga 21 Shloka 23

पुत्र O son, काश्यपः Kasyapa, जननीम् his mother, शुश्रूषुः by serving, नियतः with selfdiscipline, स्वगृहे in his own home, वसन् while dwelling, परेण with the highest, तपसा with penance, युक्तः engaged in, त्रिदिवम् heaven, गतः went.

O son Kasyapa who led a life of selfdiscipline and served his mother at home, attained heaven credited with (the merit of) the highest penance.