The addition of the concept of the written text as opposed to the oral statement is consistent throughout the 3 Nephi redaction. It is a recognition that the New World would not have been privy to the long oral tradition of the Old World, and therefore the comparison to the Law had to come from the written text. Nevertheless, the intent of the phrasing “ye have heard it hath been said by them of old time” may have been understood as a reference to the written text, even though it was not explicit. (Robert Guelich. A Foundation for Understanding the Sermon on the Mount. Word Publishing, Dallas. 1982, p. 179-180).
The next important change is the removal of “without a cause” from the Matthean text. Even in the Matthean text, this phrase appears to have been an insertion to attempt to temper the issue of anger, as the phrase is omitted in several manuscripts. (Robert Guelich. A Foundation for Understanding the Sermon on the Mount. Word Publishing, Dallas. 1982, p. 185). The removal of this phrase restores the more accurate nature of the structural parallels, and improves the understanding of the relationship between anger and murder. The phrase was certainly added to deal with the very human emotion of anger, at times provoked naturally by other’s actions. Nevertheless, what the Savior is teaching is that any anger, regardless of the nature of the provocation, might lead to a condition that could harm the soul if it were to fester. Of course most of the times that humans are angry with one another it is a fleeting thing. The problem is not in that we might lose our temper, but that it might lead to losing our soul.
Interestingly, while Joseph removed the most obvious addition attempting to ameliorate the very strict prohibition against anger, he nevertheless attempts another kind of reconciliation. The change is small, but significant. Instead of “the judgment,” it becomes “his judgment.” The judging is moved away from the final judgment of God, and into the more human realm of interpersonal differences. Unfortunately, that change misses the point. It really is the danger of God’s judgment, and the parallels between the penalties for murder and anger tell us that both are leading to the same consequences. It is possible to read “his judgment” as related to God in the previous verse, but the more obvious referent is “his brother” that comes right before. The Matthean redaction is to be preferred.
An interesting note may be added on the Matthean text. We have the KJV translation “hell fire” where Matthew actually has a placename, Gehenna.
“Gehenna was a ravine on the West of Jerusalem, the supposed site of the fire-worship of Molech introduced by Ahaz, and later the place where the offal of the city was burnt; hence it became a symbol of the place of future punishment.” (Alan Hugh M’Neile. The Gospel According to St. Matthew. MacMillan and Co LTD, London, 1961, p. 62).