Bhashya
अथ ह वाचक्नव्युवाच ।पूर्वं याज्ञवल्क्येन निषिद्धा मूर्धपातभयादुपरता सती पुनः प्रष्टुं ब्राह्मणानुज्ञां प्रार्थयते हे ब्राह्मणाः भगवन्तः पूजावन्तः शृणुत मम वचः ; हन्त अहमिमं याज्ञवल्क्यं पुनर्द्वौ प्रश्नौ प्रक्ष्यामि, यद्यनुमतिर्भवतामस्ति ; तौ प्रश्नौ चेन् यदि वक्ष्यति कथयिष्यति मे, कथंचित् न वै जातु कदाचित्, युष्माकं मध्ये इमं याज्ञवल्क्यं कश्चित् ब्रह्मोद्यं ब्रह्मवदनं प्रति जेता—न वै कश्चित् भवेत्—इति ।एवमुक्ता ब्राह्मणा अनुज्ञां प्रददुः—पृच्छ गार्गीति ॥
In plain words
'Then Vācaknavī spoke' -- here is the story behind that single line. Yājñavalkya had already silenced her once, warning that her head would fall if she kept pressing him, and she had gone quiet out of that fear. Now she wants another turn, so she first asks the room for leave. 'Honored teachers,' she says, 'hear me out. I want to question this man again -- two questions -- if you're willing. If he can answer them for me, somehow, then truly, none of you will ever out-argue this man on the nature of Brahman. Not one of you could.' Hearing that, the Brāhmaṇas give their blessing: 'Go ahead, Gārgī.'
Close to the Sanskrit
'Then Vācaknavī spoke': having previously been forbidden by Yājñavalkya, and having desisted out of fear of her head falling off, she -- now again -- requests the Brāhmaṇas' permission to ask: 'O Brāhmaṇas, venerable and honored ones, hear my word. Come, I shall ask this Yājñavalkya two questions again, if your consent exists. If he answers -- tells -- me those two questions, somehow, then truly never, ever, among you, will anyone here be able to defeat this Yājñavalkya in a discourse on Brahman -- no one at all could be such a victor.' Thus addressed, the Brāhmaṇas granted permission: 'Ask, Gārgī.'