There is a discussion on jagat (universe) in Brahma Sutra I.i.2.
That (is Brahman) from which (are derived) the birth etc. of this
Brahma Sutra I.i.2
(So the meaning of this whole aphorism is):That omniscient and
omnipotent source must be Brahman from which occur the birth,
continuance, and dissolution of this universe that is ...
Shankaracharya writes in his Srih Jivamuktananda-lahari verse 20, The Wave of Bliss of the Liberated While Alive (published in Advaita-Prakarana-Manjari: A Bouquet of Non-Dual Texts translators Dr. H. Ramamoorthy and Nome:
brahma-satyam jagan-mithya jivo brahmaiva naparah
anena vedyam sacchastram-iti vedanta-dindimah
Brahman is the truth, the universe [...