Bhashya
अथ य एतदेव विद्वान् यथोक्त देवमुद्गीथ विद्वान् सामगायति उभौ स गायति चाक्षुषमादित्य च ।तस्यैवविद्फलमुच्यते— सोऽमुनैव आदित्येन स एष ये च अमुष्मात्पराञ्च लोका ताश्च आप्रोति, आदित्यान्तर्गतदेवो भूत्वत्यर्थ , देवकामाश्च ॥
In plain words
Now, whoever understands this and chants the Sāman with knowledge of the deity as described, truly sings of both the ocular and the solar realms. The reward for such a knower is declared: united with this very sun, he attains all the transcendent worlds beyond, having become the very deity dwelling within the sun, fulfilling all divine aspirations.
Close to the Sanskrit
Now, whoever knowing this very thing, knowing the deity as stated, sings the Sāman, both he sings—the ocular and the solar. The fruit for that knower is declared: by this very sun, he—this one—attains those worlds which are beyond that, having become the deity residing within the sun, thus, and having divine desires.