यदा वै निस्तिष्ठत्यथ श्रद्दधाति नानिस्तिष्ठञ्छ्रद्दधाति निस्तिष्ठन्नेव श्रद्दधाति निष्ठा त्वेव विजिज्ञासितव्येति निष्ठां भगवो विजिज्ञास इति ॥ ७.२०.१ ॥
In plain words
"When a man is steadfast, then he has faith; one who is not steadfast has no faith. Only one who is steadfast has faith. But one must seek to understand steadfastness." "Sir, I seek to understand steadfastness."
The commentators
Chāndogyopaniṣadbhāṣyam· bhāṣya
निष्ठा गुरुशुश्रूषादितत्परत्वं ब्रह्मविज्ञानाय ॥
In plain words
Steadfast dedication, starting with devoted service to the teacher, leads directly to the realization of Brahman.
Close to the Sanskrit
Firm dedication, beginning with service to the guru, is for the direct realization of Brahman.