“What do I mean, Ānanda, by ‘beings and the world of time and space’?
‘Time’ denotes flux and change;
‘Space’ denotes location and direction.
You already know that the directions are north, south, east, west, northeast, southeast, northwest, southwest, above, and below, while time is divided into past, present, and future. Thus locations are tenfold and the flow of time is threefold, making ten directions and three periods of time. Because beings are entangled in illusion, they constantly move about in time and space, which become interconnected.
A New Translation Buddhist Text Translation Society. The Śūraṅgama Sūtra With Excerpts from the Commentary by the Venerable Master Hsüan Hua (Kindle Locations 3277-3281).