Enchiridion · §8

μὴ ζήτει τὰ γινόμενα γίνεσθαι ὡς θέλεις, ἀλλὰ θέλε τὰ γινόμενα ὡς ἔστι καὶ ῥέουσάν σοι ἔσται ἡ ζωή.

mē zētei ta ginomena ginesthai hōs theleis, alla thele ta ginomena hōs esti kai rheousan soi estai hē zōē.

Do not seek for things to happen as you wish, but wish for things to happen as they are, and you will have a tranquil flow of life.

— Enchiridion 8

Source: Greek (Schenkl/Oldfather critical edition tradition) + Long 1877 English translation