διαγωνιστέον
From LSJ
τί δὲ βλέπεις τὸ κάρφος τὸ ἐν τῷ ὀφθαλμῷ τοῦ ἀδελφοῦ σου, τὴν δὲ ἐν τῷ σῷ ὀφθαλμῷ δοκὸν οὐ κατανοεῖς → why do you look at the speck of sawdust in your brother's eye and pay no attention to the plank in your own eye | and why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye | why do you see the speck that is in your brother's eye, but don't consider the beam that is in your own eye
English (LSJ)
one must make a great effort, Ph.2.471.
Spanish (DGE)
1 hay que esforzarse Ph.2.471, Dsc.Ther.p.55, c. inf. σπουδαστέον καὶ δ. ... φυλάττειν Mac.Aeg.Ep.magn.245.6.
2 hay que combatir τούτους Procl.Theol.Plat.1.33.13.
Greek (Liddell-Scott)
διαγωνιστέον: ῥημ. ἐπίθ., πρέπει τις ἰσχυρῶς νὰ προσπαθήσῃ, Φίλων 2. 471.
