Parallel
Luke 11:30
Patriarchal Greek New Testament (1904) · Berean Standard Bible
καθὼς γὰρ ἐγένετο Ἰωνᾶς σημεῖον τοῖς Νινευΐταις, οὕτως ἔσται καὶ ὁ υἱὸς τοῦ ἀνθρώπου τῇ γενεᾷ ταύτῃ σημεῖον.
For as Jonah was a sign to the Ninevites, so the Son of Man will be a sign to this generation.