τὸ ἐμόν γ' ἐμοὶ λέγεις ὄναρ → you are telling me what I know already, you are telling me my own dream
prae-signo: āre, v. a.,
I to mark before (ante-class. and post-Aug.): ad summum praesignato (al. pertundito), Cato, R. R. 154: furunculos, Plin. 28, 4, 7, § 36.
præsignō, āvī, ātum, āre, tr., marquer auparavant : Plin. 28, 36.