The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Verse 224

एष ह वा उदक्प्रवणो यज्ञो यत्रैवंवि-द्ब्रह्मा भवत्येवंविद् ह वा एषा ब्रह्माण-मनुगाथा यतो यत आवर्तते तत्तद्गच्छति ॥

In plain words

This indeed is the sacrifice that slopes toward the north, where the priest presiding as the Brahman knows this truth. And concerning that knowledgeable priest, there is this traditional song: from whatever point the sacrifice falters, he reaches and repairs it.

Close to the Sanskrit

This indeed is the sacrifice sloping northward, where a Brahman priest knowing thus becomes; knowing thus indeed is this following song regarding the Brahman priest, from whatever point he turns away, that very thing he goes.