प्राणेन रक्षन्नवरं कुलायं बहिष्कुला- यादमृतश्चरित्वा ।स ईयतेऽमृतो यत्र कामँ हिरण्मयः पुरुष एकहँसः ॥ १२ ॥
In plain words
Guarding this lower nest by the breath of life, and roaming free outside it as the immortal one he already is, he goes wherever he wishes -- the golden person, the one swan.
Close to the Sanskrit
Guarding the lower nest by means of prāṇa, having roamed outside the nest as the immortal one, he, the immortal, goes wherever he wishes — the golden person, the one swan.