अपांसोम्य पीयमानानां योऽणिमा स उर्ध्वः समुदीषति सा प्राणो भवति ॥ ६.६.३ ॥
In plain words
Of water that is drunk, my dear, the finest part rises upward and becomes breath.
The commentators
Chāndogyopaniṣadbhāṣyam· bhāṣya
तथा अपां सोम्य पीयमानानां यो अणिमा, स ऊर्ध्वः समुदीषति, स प्राणो भवतीति ॥
In plain words
In the same way, O gentle one, of the water that is drunk, whatever subtle essence rises upward becomes the vital breath.
Close to the Sanskrit
Thus of waters being drunk, O gentle one, whichever subtle essence rises upward, that becomes the vital breath, thus.