σιδηραγωγός
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
