Before commencing Brahmajigyaasa from Sri Sri Shankara bhagavadpada

एवमयमादिरनंतो नैसर्गिको अध्यासो मिथ्याप्रत्ययरूपः
कर्तृत्वभोक्तृत्वप्रवर्तकः सर्वलोकप्रत्यक्षः
अस्यानर्थहेतोः प्रहाणाय आत्म एकत्व
विद्याप्रतिपत्तये सर्वे वेदांता आरभ्यंते
यथा च अयमर्थः सर्वेषां वेदांतानां अथा
वयमस्यां शरीरकमीमांसायां प्रदर्शयिष्यामः
वेदांतमीमांसशास्त्रस्य व्याचिख्यासितस्येदमादिमं सूत्रं....

EvamayamaadiranantaO naisargikO adhyaasO mithyaapratyayaroopaha
kartrutwabhOktrutwapravartakaha sarvalOkapratyakShaha
asyaanarthahEtOho prahaaNaaya aatma Ekatwa
vidyaapratipattayE sarvE vEdaantaa aarabhyante
yathaa ca ayamarthaha sarvEShaam vEdaantaanaam athaa
vayamasyaam shareerakmeemaamsaayaam pradarshayishyaamaha
vedaantameemaamsashaastrasya vyachikyaasitasyEdamaadimam sootram

Shloka Meaning

This doesn't have a beginning nor an ending and by nature it is in the form of an illusion
it creates, enjoys, rewrites and is present in all the worlds
hence in order to reach that it requires the oneness of the aatma or the soul
which all the vedaantas or the upanishads preach in the form of lessons
as we can understand in the vedaantaas or the upanishads
that imbibes and famously visualizes the natural duties of the beings
alongwith the principles of the vedaantas we will understand more in these sutras

Here, Sri Sri Shankara Bhagavadpada is already talking about who this Brahma is, with a slight introduction, he plunges into the chapter of "Brahma Jigyaasa" mentioning it as "Athaa to brahmajigyaasa'. By reciting these, he is actually translating the 'Brahma Sutras', making it easier for the normal humans to understand what are those hidden treasures in the scripts that talks about something which cannot be seen and is called  known as 'Brahma' from ages.