The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Verse 161

अरिष्ट कोश प्रपद्येऽमुनामुनामुना प्रा-ण प्रपद्येऽमुनामुनामुना भू प्रपद्येऽमुनामुनामुना भुव प्रपद्येऽमुनामुनामुना स्वप्रपद्येऽमुनामुनामुना ॥ ३ ॥

In plain words

I take refuge in the unbroken sheath, calling upon you by this name and that; I take refuge in prana, in earth, in the atmosphere, and in heaven, calling upon you by this name and that.

Close to the Sanskrit

I enter the safe sheath by such and such; I enter prana by such and such; I enter bhu by such and such; I enter bhuvas by such and such; I enter svar by such and such.