προσέχειν τὸν νοῦν
From LSJ
Ubi idem et maximus et honestissimus amor est, aliquando praestat morte jungi, quam vita distrahi → Where indeed the greatest and most honourable love exists, it is much better to be joined by death, than separated by life.
Greek > English (Woodhouse)
heed, mark, note, notice, apply one's mind to, attend to, bestow attention, pay attention to, pay attention