Meditations 4.43

Time is like a river made up of the events which happen, and a violent stream; for as soon as a thing has been seen, it is carried away, and another comes in its place, and this will be carried away too.

Marcus Aurelius, Meditations 4.43, translated by George Long

As a river consisting of all things that come into being, aye, a rushing torrent, is Time. No sooner is a thing sighted than it is carried past, and lo, another is passing, and it too will be carried away.

Marcus Aurelius, Meditations 4.43, translated by C. R. Haines