Matthew 5:22
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,
Sanhedrin 100a
Babylonian TalmudSometime later that student’s ship set sail at sea. He saw the ministering angels cutting precious stones that size. He said to the angels: For whom are these stones? The angels said to him: The Holy One, Blessed be He, is destined to place them at the gates of Jerusalem. When the student returned, he found Rabbi Yoḥanan, who was sitting and teaching. The student said to him: My teacher, teach, and it is fitting for you to teach. Just as you said with regard to the precious stones, so I saw. Rabbi Yoḥanan said to him: Good-for-nothing, if you did not see it, you would not believe it? You are one who mocks the statements of the Sages. Rabbi Yoḥanan directed his eyes toward him in anger and rendered him a pile of bones.
Notes and References
"... The derogatory use of “fool” as a slur is not very common, appearing in relation to a handful of people who are criticized for foolish behavior (Babylonian Talmud ‘Avodah Zarah 51a) or foolish sayings (b. Chullin 85b; b. Niddah 52b). Most notably, it is used against specific groups, such as the Sadducees ... scholars such as Guelich have marked it as the Hebrew/Aramaic lexical equivalent of μωρέ (mōre) in Matthew, and it could well have been the term translated by the Greek.53 However, the word used by Matthew, raka, has an equivalent in rabbinic literature as well. It is used in several sources (such as Mekhilta deRabbi Ishmael, Baḥodesh 5; b. Ta’anit 20a; b. Berakhot 22a; b. Gittin 58a; b. Bava Kamma 50b) as a general insult without the added context one finds with the word shaṭya or shoṭe. In a few instances, however, even this term is used in contexts that suggest added hostility: in the Babylonian Talmud, Sanhedrin 100a, a student is doubtful of a rabbinic tradition about God’s future fantastic deeds. After the student has a vision that confirms the truth of the tradition, he tells R. Yoḥanan about his vision and is criticized for only believing after seeing. The student is called “a fool,” אקיר (reqa) and “one who mocks rabbinic teachings” and is promptly turned into a pile of bones ..."
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