You cannot step twice into the same river.
ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ
Original text (Ancient Greek)
Notes from Wikiquote
Plutarch, On the EI at Delphi
Original text (Ancient Greek)
Change he called a pathway up and down, and this determines the birth of the world.
You could not step twice into the same river; for other waters are ever flowing on to you.
Quote text and notes from Wikiquote: Heraclitus (page history), available under CC BY-SA 4.0. Source quality and labels are our own summary of what Wikiquote records.