Matthew 5: 22: the insult "fool" and the interpretation of the law in Christian and rabbinic sources

The use of sources outside the New Testament, from the writings of Qumran to those of the rabbis, can help clarify the semantic and theological ield in which Matthew 5: 22 should be understood. This article claims that the correct interpretation of the Law stood at the center of arguments between different groups in the late Second Temple period and later; that the insults raka "empty" and more "fool" are connected to this polemical environment; and that it is within this setting that the Sermon on the Mount should be understood.