तद्वा एतदनुज्ञाक्षरं यद्धि किंचानुजानात्योमित्येव तदाहैषो एव समृद्धिर्यदनुज्ञा समर्धयिता ह वै कामानां भवति य एतदेवं विद्वानक्षरमुद्गीथमुपास्ते ॥ १.१.८ ॥
In plain words
This is the syllable of assent; for whenever a man assents to anything he says Om. And assent is prospering. He becomes one who makes desires prosper who, knowing this, worships the syllable as the Udgītha.
The commentators
Chāndogyopaniṣadbhāṣyam· bhāṣya
ज्ञाया , समृद्धो हि ओमित्यनुज्ञा ददाति , तस्मात् समृद्धिगुणवानोंकार इत्यर्थ । समृद्धिगुणोपासकत्वात् तद्धर्मा सन् समर्थयिता ह वै कामानां यजमानस्य भवति, य एतदेवं विद्वानक्षरमुद्गीथमुपास्ते इत्यादि पूर्ववत् ॥
In plain words
Because Om grants assent with abundance, the syllable is endowed with prosperity. Through meditating on this quality of abundance, the worshipper takes on that very nature and truly becomes a granter of desires for the sacrificer, knowing and meditating on the imperishable syllable as the Udgitha, just as stated before.
Close to the Sanskrit
By knowledge, for Om grants assent with abundance; therefore the meaning is that Om possesses the quality of abundance. Because of meditating on the quality of abundance, sharing that nature, he truly becomes a fulfiller of desires for the sacrificer—he who, knowing this thus, meditates on the imperishable syllable as the Udgitha, and so forth, as before.