Shiva Purana

siva.sh/siva-purana/uma-samhita/29/11

आपो नारा इति प्रोक्ता आपो वै नरसूनवः ।। अयनं तस्य ताः पूर्वं तेन नारायणः स्मृतः ।। ११ ।।

sanskrit

The waters are called Nāra (belonging to Nara). The waters are the progenies of Nara. Since waters had been his abode he is called Nārāyaṇa.

english translation

Apo nArA iti proktA Apo vai narasUnavaH || ayanaM tasya tAH pUrvaM tena nArAyaNaH smRtaH || 11 ||

hk transliteration by Sanscript