स यस्तेजो ब्रह्मेत्युपास्ते तेजस्वी वै स तेजस्वतो लोकान्भास्वतोऽपहततमस्कानभिसिध्यति यावत्तेजसो गतं तत्रास्य यथाकामचारो भवति यस्तेजो ब्रह्मेत्युपास्तेऽस्ति भगवस्तेजसो भूय इति तेजसो वाव भूयोऽस्तीति तन्मे भगवान्ब्रवीत्विति ॥ ७.११.२ ॥
In plain words
He who worships heat as Brahman becomes full of heat and attains worlds full of heat and light, free of darkness. He moves at will so far as heat reaches, who worships heat as Brahman. "Is there, sir, anything greater than heat?" "There is indeed something greater than heat." "Tell me that, sir."
The commentators
Chāndogyopaniṣadbhāṣyam· bhāṣya
तस्य तेजस उपासनफलम्-तेजस्वी वै भवति । तेजस्वत एव च लोकान्भास्वतः प्रकाशवतः अपहततमस्कान् बाह्याध्यात्मिकाज्ञानाद्यपनीततमस्कान् अभिसिध्यति । ऋज्वर्थमन्यत् ॥
In plain words
The result of meditating on light is this: a person becomes truly radiant. He attains realms of light that shine brilliantly, stripped of all outer and inner ignorance and every trace of darkness. The remainder of the text is clear on its own face.
Close to the Sanskrit
Of that meditation on tejas, the result: one becomes radiant indeed. And he attains radiant worlds, shining, full of light, having destroyed darkness, from which external and internal ignorance and other darkness have been removed. The rest is straightforward in meaning.