ἔγνω δὲ φώρ τε φῶρα καὶ λύκος λύκον → the thief knows the thief and the wolf knows the wolf, and thief knows thief and wolf his fellow wolf, set a thief to catch a thief

[spiros]

le voleur connaît le voleur et le loup le loup → the thief knows the thief and the wolf knows the wolf
Callimaque / Epigrammes, XLIII, 6

έγνω δε φωρ τε φώρα και λύκος λύκον
ἔγνω δὲ φώρ τε φῶρα καὶ λύκος λύκον
вор узнает вора, а волк - волка

ἀπορεῖται δὲ πολλὰ περὶ τῆς φιλίας, πρῶτον μὲν ὡς οἱ [5] ἔξωθεν παραλαμβάνοντες καὶ ἐπὶ πλέον λέγοντες: δοκεῖ γὰρ τοῖς μὲν τὸ ὅμοιον τῷ ὁμοίῳ εἶναι φίλον, ὅθεν εἴρηται“ὡς αἰεὶ τὸν ὅμοιον ἄγει θεὸς ὡς τὸν ὅμοιον” Hom. Od. 17.218 “καὶ γὰρ κολοιὸς παρὰ κολοιόν:” “ἔγνω δὲ φώρ τε φῶρα, καὶ λύκος λύκον.”
Ηθικά Ευδήμεια/7 - Βικιθήκη

φώρ - Ancient Greek (LSJ)

[bailongma]

ἔγνω < γιγνώσκω -- 3rd. sing. aorist ind. active
φώρ -- sing. m. nom. "thief"
φῶρα -- sing. acc. "theif"
τε... καὶ -- shows parallelism; "both... and"
λύκος -- sing. nom. "wolf"
λύκον -- sing. acc. "wolf"

The question might be "well why is ἔγνω an aorist" -- to which I reply (perhaps incorrectly): it is the gnomic aorist

Thus: ἔγνω δὲ φώρ τε φῶρα καὶ λύκος λύκον
"a thief [φώρ] recognises [ἔγνω] a thief [φῶρα] and a wolf [λύκος] a wolf [λύκον]"

the "τε... καὶ" helps to show that "ἔγνω" goes with both pairs of thief/thief and wolf/wolf, hence why there is no need to write out a verb for "λύκος λύκον"