Who said "Watch yourself like an enemy lying in ambush."?

Epictetus (c. 50–135 AD). Source: Enchiridion 48.

What is the original Greek?

ὡς ἐχθρὸν ἑαυτὸν παραφυλάσσει καὶ ἐπίβουλον. Translated from the original Greek by Spartan Surfers.

Watch yourself like an enemy lying in ambush.

Epictetus, Enchiridion 48

The source

"Watch yourself like an enemy lying in ambush." Epictetus said it in Enchiridion 48. Translated from the original Greek by Spartan Surfers.

"ὡς ἐχθρὸν ἑαυτὸν παραφυλάσσει καὶ ἐπίβουλον."

Original Greek, Enchiridion 48. Greek: Schenkl 1916 (Teubner) via Perseus.

Who said it

Epictetus (c. 50–135 AD). Born enslaved, became the most influential Stoic teacher of his age. His student Arrian wrote down the Discourses and the Enchiridion.

Questions

Who said "Watch yourself like an enemy lying in ambush."?: Epictetus (c. 50–135 AD). Source: Enchiridion 48.
What is the original Greek?: ὡς ἐχθρὸν ἑαυτὸν παραφυλάσσει καὶ ἐπίβουλον. Translated from the original Greek by Spartan Surfers.