The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 351

ॐ ऋतं सत्यं परं ब्रह्म पुरुषं नृके-सरिविग्रहम् ।कृष्णपिङ्गलमूर्ध्वरेतं वि-

In plain words

Om. Truth itself, order itself, the highest Brahman -- the Person, wearing the form of the Man-Lion. Dark in one part, tawny in another, his life-energy gathered upward, never spent --

Close to the Sanskrit

Om. The cosmic order, the truth, the supreme Brahman, the Person, embodied in the form of the Man-Lion; dark and tawny [in hue], of upward-flowing energy, [who] --