Notes on Brahma-Sutra by Foreward by T.M.P. Mahadevan:

 

I-i-10: In all the Upanishads, Consciousness is apprehended uniformly as the cause, as for instance in the texts: "As from a burning fire, the sparks fly diversely in different directions, similarly from this Self all the senses and organs originate in their respective loci. After the senses originate their presiding deities and after the deities emerge the sense-objects" (Kausitaki Upanishad III-8), "from that very Self, that is such, originated space" (Taittiriya Upanishad II-1), "From the Self indeed came all this" (Chandogya VII-xxvi-1), "From the Self emerges this vital force" (Prasna III-3), etc., where all the Upanishads reveal the Self as the cause. And we said that the word "Self" implies a conscious entity. This also is a great proof of the validity of the Upanishads, that just like the eyes etc., imparting the same kind of knowledge about colour etc., the Upanishads also impart the same kind of knowledge about the Self’s being the cause of the universe. Hence it follows from the uniformity in the trend (of the meaning imparted) that omniscient Brahman is the cause of the universe.