Matthew 5:21
21 “You have heard that it was said to an older generation, ‘Do not murder,’ and ‘whoever murders will be subjected to judgment.’ 22 But I say to you that anyone who is angry with a brother will be subjected to judgment. And whoever insults a brother will be brought before the council, and whoever says ‘Fool’ will be sent to fiery hell. 23 So then, if you bring your gift to the altar and there you remember that your brother has something against you, 24 leave your gift there in front of the altar. First go and be reconciled to your brother and then come and present your gift. 25 Reach agreement quickly with your accuser while on the way to court, or he may hand you over to the judge, and the judge hand you over to the warden, and you will be thrown into prison. 26 I tell you the truth, you will never get out of there until you have paid the last penny!
Bava Metzia 58b
Babylonian TalmudThe Gemara relates that the tanna who recited mishnayot and baraitot in the study hall taught a baraita before Rav Naḥman bar Yitzḥak: Anyone who humiliates another in public, it is as though he were spilling blood. Rav Naḥman bar Yitzḥak said to him: You have spoken well, as we see that after the humiliated person blushes, the red leaves his face and pallor comes in its place, which is tantamount to spilling his blood. Abaye said to Rav Dimi: In the West, i.e., Eretz Yisrael, with regard to what mitzva are they particularly vigilant? Rav Dimi said to him: They are vigilant in refraining from humiliating others, as Rabbi Ḥanina says: Everyone descends to Gehenna except for three.
Notes and References
"... To call a brother or a sister a “fool” meant, according to Garlington, condemning him unjustly. Such a condemnation deserves, as stated by Jesus, a trial for murder. Even if one does not fully accept this last suggestion, it seems, therefore, that the use of the insult “fool” carried particular content when used in this environment. It is an insult meant to signal a certain type of opponent understood in a specific theological context. But even if we do not turn to the theological ramification of this insult, recent scholarship has urged us to consider the more general function of such insults in the culture of the ancient world. Slurs such as “fool” should not be seen as mere harmless words, but rather as “genuine social weapons intended to cause serious injury.” When uttered by influential persons, the use of such negative labelling can cause real damage. And as such, later rabbinic law, for example, deems it worthy of punishment in courts, and one Talmudic saying even compares public insults to spilling blood. (B. Baba Mes'ia 58b) ..."
Siegal, Michael Bar-Asher Matthew 5:22: The Insult "Fool" and the Interpretation of the Law in Christian and Rabbinic Sources (pp. 5-23) Revue de l'Histoire des Religions, 2017