Those who heard Jesus’ words knew that the command not to murder had applied from ancient times, and that individuals guilty of murder would face severe judgment. (Matthew 5:21) The law also indicated that certain acts were tantamount to murder, as they were expressions of violent rage. The penalty for murder, for example, was imposed on anyone who struck his father or mother or cursed either one of them. (Exodus 21:15, 17) Accordingly, the command prohibiting murder had as its intent more than restraining individuals from going to the point of killing someone, and Jesus made this clear in his teaching.
Anyone who continued in a state of wrath toward his brother would make himself liable for judgment (like one guilty of an offense that merited judicial action). The hearers likely would have understood the “brother” to have been a fellow Israelite, one related to them by reason of their common descent from Jacob or Israel. (Matthew 5:22)
Even more serious would be calling a brother rhaká (an expression of abuse, which may be a transliteration of an Aramaic term meaning “empty one” and conveying the sense of such abusive terms as “numskull,” “nitwit,” or “stupid”). According to Jesus’ teaching, the person who used such abusive language made himself guilty of an offense comparable to a crime that was serious enough for the Sanhedrin or Jewish supreme court to handle. (Matthew 5:22)
Anyone who called his brother a “fool,” or condemned him as a morally worthless person deserving of the severest punishment, would make himself liable for Gehenna. (Matthew 5:22) Instead of loving his brother, the individual would be showing extreme hatred for him, regarding him as a person unfit to continue living. Therefore, the judgment such a hateful person wished to befall his brother would, in keeping with retributive justice, be expressed against him. One who experienced the judgment of Gehenna would come to be like a carcass tossed on a garbage heap and would remain in a state of condemnation, forever deprived of the eternal life of fellowship with God and Christ. (Compare Isaiah 66:24.)
In Matthew 5:22, the Greek participle for “being angry” is in the present tense and so suggests a continued state of anger. Numerous manuscripts include the word eiké, meaning “for no reason,” and thus imply that there might be justification for being angry. It appears likely that this was a scribal attempt to make Jesus’ statement less all-embracing. The word is missing in such ancient manuscripts as partially preserved P67 (second century) and fourth-century Codex Vaticanus.
In the Scriptures, the designation “fool” relates primarily to one who is morally corrupt. Isaiah 32:6, 7 (NJB) describes such a person as follows: “For the fool speaks folly and his heart is set on villainy; he is godless in his actions and his words ascribe error to Yahweh; he starves the hungry of their food and refuses drink to the thirsty. Everything to do with the rascal is evil, he devises infamous plans to ruin the poor with lying words even when the needy has right on his side.”
Gehenna is evidently to be linked to the Valley of Hinnom, where unfaithful Israelites anciently engaged in idolatrous rites. Godly king Josiah eradicated idolatry and defiled the location, at which time or later the valley came to be used as a refuse dump. (2 Kings 23:10) It appears that this is the reason fire and worms or maggots are associated with Gehenna, and the judgment of Gehenna denotes the severest punishment possible.