In plain words
Neither by study of the Vedas and yajñas, nor by gifts, rites, or severe tapas can I be seen in this form in the human world by anyone other than you, foremost of Kurus.
Word for word
Not by the study of the Vedas and of sacrifices, not by gifts, nor by rites, nor by fierce austerities can I in such a form be seen in the world of men by any other than you, O foremost hero of the Kurus.
न वेदयज्ञाध्ययनैर्न दानैःन च क्रियाभिर्न तपोभिरुग्रैःएवंरूपः शक्य अहं नृलोकेद्रष्टुं त्वदन्येन कुरुप्रवीर
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam
आत्मनः मम रूपदर्शनेन कृतार्थ एव त्वं संवृत्तः इति तत् स्तौति —
न वेदयज्ञाध्ययनैः चतुर्णामपि वेदानाम् अध्ययनैः यथावत् यज्ञाध्ययनैश्च — वेदाध्ययनैरेव यज्ञाध्ययनस्य सिद्धत्वात् पृथक् यज्ञाध्ययनग्रहणं यज्ञविज्ञानोपलक्षणार्थम् — तथा न दानैः तुलापुरुषादिभिः, न च क्रियाभिः अग्निहोत्रादिभिः श्रौतादिभिः, न अपि तपोभिः उग्रैः चान्द्रायणादिभिः उग्रैः घोरैः, एवंरूपः यथादर्शितं विश्वरूपं यस्य सोऽहम् एवंरूपः न शक्यः अहं नृलोके मनुष्यलोके द्रष्टुं त्वदन्येन त्वत्तः अन्येन कुरुप्रवीर ॥ ४८ ॥
In plain words
"In seeing my form — the form of the Self — you have already become someone with nothing left to seek." With these words he praises that vision:
You cannot reach this form of mine through Vedic study, however complete, through mastering all four Vedas, through studying the sacrifices in the proper way — and Śaṅkara adds a small note: since studying the Vedas already covers the sacrifices, mentioning sacrifice separately is just to point at real understanding of what sacrifice means, not mere recitation. Nor can you reach it through giving gifts, however lavish. Nor through ritual acts, even the great fire-offerings the scriptures prescribe. Not even through the fiercest austerities, the harshest fasts. This form of mine that I showed you — no one in this human world can see it. No one but you, Arjuna, best of the Kurus. No one at all.
Close to the Sanskrit
"By the seeing of my form, the form of the Self, you have indeed become one whose purpose is accomplished" — thus he praises that:
Not by study of the Vedas and sacrifices — by study of all four Vedas properly, and by study of sacrifices [rites; since the accomplishment of sacrificial study is already achieved by Vedic study alone, the separate mention of 'study of sacrifice' is for the purpose of indicating knowledge of sacrifice] — likewise not by gifts such as the gift of one's weight in gold, nor by rites such as the fire-oblation, prescribed by Vedic revelation, nor even by austerities, fierce ones, such as the lunar-fast, fierce, terrible ones — I, of such a form, whose universal form has been shown as described, such a one, am not able to be seen in the world of men, the human world, by anyone other than you, apart from you, by another, O foremost of the Kurus.