ὕπνος δεινὸν ἀνθρώποις κακόν → sleep is a terrible evil for humans (Menander, Sententiae monostichoi 1.523)
sure: P. and V. πιστός, ἀσφαλής, ἐχέγγυος (Thuc. but rare P.), φερέγγυος (Thuc. but rare P.).
incessant: V. διατελής; see incessant.