συγγνωστέον
From LSJ
Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
Greek (Liddell-Scott)
συγγνωστέον: ἢ -έα, ῥημ. ἐπίθ. τοῦ συγγιγνώσκω, δεῖ συγγιγνώσκειν, τινὶ Πλάτ. Φαῖδρ. 236Α.
