Adi Shankara Bhagavatpada (~ 788 - 820 CE) was a traditional teacher, a philosopher, a commentator (bhāṣyakara) of the highest caliber who expounded and commented upon the teachings of the Bhagavad Gita, the principal Upanishads, and the Brahma Sutras, usually known as Prasthanatraya. Many more writings (Prakaranagranthas), and devotional hymns (stotras) are commonly attributed to him. One of his direct disciples, Sri Sureśvarācārya humbly wrote:
श्रीमच्छङ्करपादपद्मयुगलं संसेव्य लब्ध्वोचिवान्
ज्ञानं पारमहंस्यमेतदमलं स्वान्तान्धकारापनुत् ।
Sri Sureśvarācārya, Naiṣkarmyasiddhi 4.74
"Having served the lotus feet of Sri Adi Śankaracharya Bhagavatpada, I gained this pure knowledge of the Paramahamsas and it eliminated the inner darkness (ignorance) of my soul (misunderstanding)."
In Pujya Swami Dayananda ji words:
"To talk on Śaṅkara is to unfold what Īśvara, the Lord is. We do not look upon Śaṅkara as an individual. In fact, we do not look upon any teacher as an individual."
Swami Dayananda. Talks and Essays One. Arsha Vidya Research and Publication Trust.
More about Adi Shankara Bhagavatpada:
https://www.satsang.avgmedia.org/sri-sankara/
श्रीमच्छङ्करपादपद्मयुगलं संसेव्य लब्ध्वोचिवान्
ज्ञानं पारमहंस्यमेतदमलं स्वान्तान्धकारापनुत् ।
Sri Sureśvarācārya, Naiṣkarmyasiddhi 4.74
"Having served the lotus feet of Sri Adi Śankaracharya Bhagavatpada, I gained this pure knowledge of the Paramahamsas and it eliminated the inner darkness (ignorance) of my soul (misunderstanding)."
In Pujya Swami Dayananda ji words:
"To talk on Śaṅkara is to unfold what Īśvara, the Lord is. We do not look upon Śaṅkara as an individual. In fact, we do not look upon any teacher as an individual."
Swami Dayananda. Talks and Essays One. Arsha Vidya Research and Publication Trust.
More about Adi Shankara Bhagavatpada:
https://www.satsang.avgmedia.org/sri-sankara/