He guarded Sutra

There is a supreme (Mahan) way that puts an end (Násana) to the fear (Bhaja) of worldly existence. Through this you cross the ocean of Samsara and attain Supreme Salvation (Paramánanda). Meditating on the meaning of Vedanta (Vicšara) leads to effective knowledge (Gjána-uttama), the immediate result of which is the complete annihilation (Átjantika) of the suffering born from worldly existence (Ssamsára). Sankarácsárja: Viveka-cúdámani 44-45. Vedanta means the culmination of the Vedic and Upanishad literature, while the word Sutra means guiding thread. The term Vedanta denotes the Upanishad literature and its ultimate essence. The Upanishad literature is the repository of the various philosophical currents of ancient India, and that is why the summation, which was realized in the Vedanta Sutra, became necessary. The Sútra-style is a very special genre, which strives to harmonize doctrinal systems that have often been in philosophical debate for centuries. However, despite its encyclopedic nature, the Vedantic Sutra is not obscure or impractical, if properly presented, it will be a source of immediate inspiration. His comprehensive, universal vision is able to lift the mind out of the limitations of the materialistic body-mind (Saríra-Manasz) conception of life and lead it to the realization of the ultimate freedom, the Supreme Absolute (Para-Brahman). Since diversity is the object of our everyday perception, it became necessary to explain that everything is actually the Absolute, Brahman, which is one without a second, while the diversity of the world of phenomena is only apparent (Maya). This is what the Vedanta Sutra preaches. Brahman is the only reality (Satyam), the world (Jagat) is unreal (Mithya), the individual soul (Jiva) is essentially non-different (Napara) from Brahman. Sankaracsarya: Brahma Gnanavali Mala 20. (excerpt)