अथ य एष संप्रसादोऽस्माच्छरीरा त्समुत्थाय परं ज्योतिरूपसंपद्य स्वेन रू पेणाभिनिष्पद्यत एष आत्मेति होवाचै तदमृतमभयमेतद्ब्रह्मेति तस्य ह वा एत स्य ब्रह्मणो नाम सत्यमिति ॥ ४ ॥
In plain words
Now, this serene Self, rising up from the physical body and reaching the supreme light, shines forth in its own true nature. 'This is the Self,' he declared, 'this is the immortal, the fearless, this is Brahman.' And indeed, the name of this very Brahman is Satyam—the True.
Close to the Sanskrit
Now, this serene being, having risen up from this body, and having attained the supreme light, becomes manifest in its own form—this is the Self, thus he spoke; this is the immortal, the fearless, this is Brahman; of this very Brahman indeed the name is Satyam.