The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Verse 42

तस्यर्क्च साम च गेष्णौ तस्मादुद्गीथ-

In plain words

Ṛk and Sāman are the two limbs of that Udgītha; therefore...

Close to the Sanskrit

Of that [Udgītha], Ṛk and Sāman are the two limbs; therefore Udgītha...