Matthew 9:3

βλασφημεῖν. Construction τινά, εἴς τινα, τι or abs. (1) to speak evil of God or of sacred things βλ. εἰς τὸ πνεῦμα τὸ ἅγιον, Mark 3:29 and Luke 12:10; ἠνάγκαζον βλασφημεῖν, Acts 26:11; ἵνα μὴ ὁ λόγος τοῦ Θεοῦ βλασφημῆται, Titus 2:5. (2) to disparage the divine nature, to usurp the honour due to God, as here and generally in the Gospels. (3) ‘to calumniate men’ τί βλασφημοῦμαι ὑπὲρ οὖ ἐγὼ εὐχαριστῶ; 1 Corinthians 10:30. As a classical word βλασφημεῖν is opposed to εὐφημεῖν: so βλασφημία, Eur. Ion. 1189, βλασφημίαν τις οἰκετῶν ἐφθέγξατο, ‘spake word of evil omen.’ The derivation is uncertain, perhaps from the same root as βλάξ, βλάζειν, see Buttmann, Lex, sub voc. βλίττειν, § 6. Others connect the word with βλάπτειν, cp. ‘all words that may do hurt.’