प्राणस्य प्राणमुत चक्षुषश्चक्षुरुत श्रो-त्रस्य श्रोत्रं मनसो ये मनो विदुः ।तेनिचिक्युर्ब्रह्म पुराणमग्र्यम् ॥ १८ ॥
In plain words
The breath behind the breath, the eye behind the eye, the ear behind the ear, the mind behind the mind — whoever knows this has truly found Brahman, ancient beyond measure, first of all.
Close to the Sanskrit
Of breath, the breath; and of the eye, the eye; and of the ear, the ear; of the mind, the mind — those who know it thus have discerned Brahman, the ancient, the foremost.