Mantra 3

स य एतदेवममृतं वेदादित्यानामेवैको भूत्वा वरुणेनैव मुखेनैतदेवामृतं दृष्ट्वा तृप्यति स एतदेव रूपमभिसंविशत्येतस्माद्रूपादुदेति ॥ ३.८.३ ॥

In plain words

He who knows this nectar thus becomes one of the Ādityas and, with Varuṇa for his mouth, is satisfied by merely looking upon this nectar. He enters into this form and rises out of this form.