आनन्दघनतामस्य स्वरूपं प्रत्यगात्मनः ।धन्यैर्महात्मभिर्धीरैर्ब्रह्मविद्भिः सदुत्तमैः ॥ ६६६ ॥
In plain words
The inner Self's true nature as an unbroken mass of bliss is fully known by blessed, steadfast, and great souls who are knowers of Brahman and the best of the wise.
Close to the Sanskrit
(They know) the state of being dense bliss of this essential nature of the inner Self, by fortunate, great, steady souls, knowers of Brahman, best of the virtuous.