नराज्जातानि तत्त्वानि नाराणीति ततो विदुः ।तान्येव चायनं तस्य तेन नारायणः स्मृतः ॥
In plain words
The tattvas, the principles of everything there is, were born from Nara — and so those who know call them nāra, his own. And those very principles are his ayana, the place where he dwells. Put the two together and you have his name: Nārāyaṇa.
Close to the Sanskrit
The tattvas born from Nara — 'nāras', thus, from that, they know them. And those very ones are the abode of him; by that, he is remembered as Nārāyaṇa.