Question and Answer on Brahmasutras - Mr. Anjaneyulu Gottipamula
Please explain how brahmasutras fit into Upanishads.
Brahmasutras, employing a lot of logical analysis, present the messages of the Upanishads in concise statements. They are aphorisms, sutras therefore.
Janma- aadi-asya yatah is a sutra (number 2). This means: from which birth etc. of this happens. When you elaborate it, it means Brahman the absolute reality is THAT from which the universe arises, stays and dissolves. This is the summary of four much longer sentences that are found in Taittiriya Upanishad 3rd valli.