εἰρητέον

From LSJ

Βέβαιον οὐδέν ἐστιν ἐν θνητῷ βίῳ → Nihil, ut videtur, proprium in vita datur → Nichts Festes gibt's im Leben eines Sterblichen

Menander, Monostichoi, 57

Spanish (DGE)

hay que decir Ath.Al.M.28.533B.