Śatapatha Brāhmaṇa ("of a hundred paths") 10.5.2.7

10.5.2.7

saiṣā trayyeva vidyā tapati taddhaitadapyavidvāṃsa āhustrayī vā eṣā vidyā tapatīti vāgghaiva tatpaśyantī vadati

Now as to the self (body). That shining orb and that gold plate are the same as the white here in the eye; and that glowing light and that lotus-leaf are the same as the black here in the eye; and that man in yonder orb and that gold man are the same as this man in the right eye.