What is the significance/symbolism of the Cyclical book being cyclical in “The Library of Babel”?

Question

In The Library of Babel by Jorge Luis Borges, the speaker describes the cyclical book as

(The mystics claim that their ecstasy reveals to them a circular chamber containing a great circular book, whose spine is continuous and which follows the complete circle of the walls; but their testimony is suspect; their words, obscure. This cyclical book is God.

What is the significance/symbolism behind the book being "cyclical", as opposed to a different shape?

Answer 1

In his essay on Pascal's sphere, which relates to several of the themes of "The Library Of Babel", Borges also notes the fixation certain mystics had on picturing God as an infinite sphere whose circumference is nowhere and center, everywhere. Thus, Borges is probably continuing his train of thought on this subject in that essay by making the book that represents God cyclical, as well as making the Library itself analogous to Pascal's sphere.