Bhashya
एवं राजानं शुश्रूषुम् अभिमुखीभूतं स होवाच गार्ग्यः— य एव असौ आदित्ये चक्षुषि च एकः अभिमानीचक्षुर्द्वारेण इह हृदि प्रविष्टः अहं भोक्ता कर्ता चेत्यव-स्थितः— एतमेव अहं ब्रह्म पश्यामि अस्मिन्कार्यकरणसं-घाते उपासे ; तस्मात् तमहं पुरुषं ब्रह्म तुभ्यं ब्रवीमिउपास्स्वेति ।स एवमुक्तः प्रत्युवाच अजातशत्रुः मा मेतिहस्तेन विनिवारयन्— एतस्मिन् ब्रह्मणि विज्ञेये मा संव-दिष्ठाः ; मा मेत्याबाधनार्थं द्विर्वचनम्— एवं समाने विज्ञा-नविषय आवयोः अस्मानविज्ञानवत इव दर्शयता बाधिताःस्यामः, अतो मा संवदिष्ठाः मा संवादं कार्षीः अस्मिन्ब्र-ह्मणि ; अन्यच्चेज्जानासि, तद्ब्रह्म वक्तुमर्हसि, न तु यन्मयाज्ञायत एव ।अथ चेन्मन्यसे— जानीषे त्वं ब्रह्ममात्रम्,न तु तद्विशेषेणोपासनफलानीति— तन्न मन्तव्यम् ; यतःसर्वमेतत् अहं जाने, यद्ब्रवीषि ; कथम् ? अतिष्ठाः अतीत्यभूतानि तिष्ठतीत्यतिष्ठाः, सर्वेषां च भूतानां मूर्धा शिरःराजेति वै— राजा दीप्तिगुणोपेतत्वात् एतैर्विशेषणैर्विशिष्ट-मेतद्ब्रह्म अस्मिन्कार्यकरणसंघाते कर्तृ भोक्तृ चेति अहमे-तमुपास इति ; फलमप्येवं विशिष्टोपासकस्य-स य एतमे- वमुपास्ते अतिष्ठाः सर्वेषां भूतानां मूर्धा राजा भवति ; यथागुणोपासनमेव हि फलम् ; 'तं यथा यथोपासते तदेव भवति' इति श्रुतेः ॥
In plain words
As Gārgya leaned forward, eager to instruct, he said to the king: 'The presence that shines within the sun and within the eye as one presiding consciousness—having entered the heart through the doorway of sight, dwelling here as the doer and the enjoyer—this very reality I behold as Brahman, and I meditate upon it within this psychophysical frame. Therefore, I declare that very person to be Brahman for you. Worship him.' Hearing this, King Ajātaśatru warded him off with a gesture of his hand, saying, 'Do not converse with me about this Brahman! Do not speak of it!'—the repetition emphasizes the prohibition—'If two people of equal standing in knowledge speak thus, we will appear like the ignorant and be put to shame. Therefore, do not discuss this Brahman. If you know something else, you are welcome to speak of it, but not of what I already know.' If you think, 'You know only general Brahman, but not the specific fruits of its worship,' do not think so; for I know all that you speak of. How? As Atiṣṭhā, because He stands transcending all beings, and as the head and king of all beings—for a king is radiant by nature—with these very attributes I worship this Brahman within this body-mind as the agent and experiencer. And the fruit for one who meditates with such specificity is likewise: 'Whoever meditates upon Him as Atiṣṭhā, the head and king of all beings, becomes just that.' For the result corresponds precisely to the meditation, as the Vedic text declares: 'According as a person meditates upon Him, so he becomes.'
Close to the Sanskrit
Thus Gārgya, attentive and facing the king, spoke to him: 'The very same being who is in the sun and in the eye, one and presiding, having entered here into the heart through the gate of the eye, existing as the enjoyer and doer—this very one I see as Brahman, and I meditate upon him in this psychophysical aggregate; therefore I declare that person as Brahman to you, so worship him.' Being thus addressed, Ajātaśatru replied, warding him off with his hand saying, 'Do not converse with me concerning this Brahman to be known; do not speak thus—the doubling is to prohibit—thus, when our sphere of knowledge is equal, making us appear like those who do not know, we would be put to shame, therefore do not converse on this Brahman; if you know something else, you are fit to speak of it, but not of what is known by me indeed.' Now if you suppose, 'You know mere Brahman, but not the specific results of its worship,' do not think so; because I know all this that you speak of. How? As Atiṣṭhā, because He stands transcending all beings, and as the head and king of all beings—verily, king means possessing the quality of radiance—with these specific attributes I worship this Brahman in this psychophysical aggregate as the doer and enjoyer; and the fruit for such a specific meditator is also thus: 'He who thus meditates upon Him as Atiṣṭhā, the head and king of all beings, becomes such'; for the result is indeed in accordance with the meditation, as the śruti states: 'According as a person meditates upon Him, so he becomes.'