λανθάνειν τι ποιῶν
From LSJ
Ὁ αὐτὸς ἔφησε τὸν μὲν ὕπνον ὀλιγοχρόνιον θάνατον, τὸν δὲ θάνατον πολυχρόνιον ὕπνον → Plato said that sleep was a short-lived death but death was a long-lived sleep
Greek > English (Woodhouse)
do a thing insensibly, do a thing unawares, do a thing undetected