δεῖ impersonal (δέω),
[in LXX chiefly for infin. with לְ;]
one must, it is necessary: c. inf., Mt 26:54, Mk 13:7, Ac 5:29, al.; c. acc. et inf., Mt 16:21, Mk 8:31, Jo 3:7, Ac 25:10, al.; with ellipse of acc., Mt 23:23; of acc., and inf., Mk 13:14, Ro 1:278:26; οὐ (μὴ) δεῖ (non licet), ought not, must not: Ac 25:24, II Ti 2:24; impf., ἔδει, of necessity or obligation in past time regarding a past event (Bl., § 63, 4), Mt 18:33, Lk 15:32, Jo 4:4, Ac 27:21, al.; periphr., δέον ἐστίν (as in Attic, χρεών ἐστι = χρή, v.s. δέον), Ac 19:36; id., with ellipse of ἐστίν, I Pe 1:6τὰ μὴ δέοντα (= ἃ οὐ δεῖI Ti 5:13.
SYN.: ὀφείλει, expressing moral obligation, as distinct from δεῖ, denoting logical necessity and χρή, a need which results from the fitness of things (v. Tr., Syn., § cvii, 10; Westc. on He 2:1, I Jo 2:6; Hort on Ja 3:10).