Abarim Publications' online Biblical Hebrew Dictionary
The verb קלט (qalat) means to be stunted, cut short or held back. In Arabic occurs a comparable noun that means reservoir. In the Bible our verb is used only once, in Leviticus 22:23, where it appears juxtaposed with the verb שרע (sara'), to extend, and both these verbs apply to the limbs of a malformed animal: limbs that are either too short or too long.
However, these verbs are both too rare to simply mean to be too short and to be too long, and their nuance lies in a shared deviation from a perfect mean; a shared degree of compromise on either side of freedom.
This duo of verbs is comparable to the duo of verbs that mean to be lame and to be blind, which stem from the ideas of having not enough (strength = lame) and having too much (a cataract = blind). See our article on the Greek noun τυφος (tuphos) for a lengthy look at lameness versus blindness (and autism) in the Bible.
Cities of short-cutting
From our verb קלט (qalat), meaning to be cut short, comes the important noun מקלט (miqlat), which would literally denote an agent, instrument or place of cutting short. It's the word for the kind of city that served as city of "refuge" for the involuntary manslayer. Our noun occurs just shy of two dozen times — all in Numbers 35, Joshua 20 and 21 and 1 Chronicles 6 — but is generally not very well understood.
The most fundamental principle in Mosaic law is that of reciprocity. It's probably best known as the basis for the famous eye-for-an-eye edict (Exodus 21:24) but it also sits at the heart of the Golden Rule that dictates to "treat others like you want to be treated" (Leviticus 19:18, Matthew 7:12).
If a person deliberately killed another person, the rule of reciprocity kicked in and a life was demanded for a life (Genesis 9:6, Exodus 21:21), and the perpetrator was to be killed by the community headed by the victim's family. The crucial element of all this is the deliberateness of the killing: by hitting the victim with an iron object, with a stone, or with a wooden object, by pushing him or striking him with one's hand, the killer was considered a willful murderer and was to be willfully murdered.
The "city of short-cutting" solves the problem that arises when someone accidentally kills someone, because how do you accidentally kill that person in return?
An accidental killer can not be deliberate killed, and so he was banned in stead to a city of short-cutting. His biological life would continue, but his communal life was terminated. His wife became a widow and his lands and business would fall into disarray or would be appropriated by his heir. Should he venture out of his city of short-cutting, the avenger of his victim was free to execute him.
Anger and revenge
It's often thought that Mosaic law proscribed cities of short-cutting to protect accidental killers from the violent rage of the victim's vindictive family but that's incorrect. "Revenge is Mine," said YHWH rather clearly (Deuteronomy 32:35, Romans 12:19), and Israelite consciousness was permeated with the understanding that the killing of a human being was the most horrendous act anyone could perform, and executing even a murderer was a horrendous necessity.
Anger was considered a perfectly useless emotion that only brought about destruction and failure, and was subsequently deeply frowned upon: Simeon and Levi lost their right to their own tribal territories not because they avenged Dinah but because they did so in anger (Genesis 49:7). Moses lost his access to the Promised Land because he struck the rock at Meribah in anger (Numbers 20:11-12). "Fools give full vent to their anger, but the wise bring calm in the end" (Proverbs 29:11). "Anger resides in the lap of fools" (Ecclesiastes 7:9). "Refrain from anger and turn from wrath" (Psalm 37:8). "Turn the other cheek" (Matthew 5:39).
The purpose of executing a willful murderer was to purge Israel from murderous rage, and the purpose of the cities of short-cutting was to purge Israel from irresponsible carelessness. When rage became so vehement that it lead to murder, the murderer was beyond redemption. But a fool whose stupidity blossomed in unfortunate circumstances, could still be redeemed. The cities of short-cutting were peopled by Levites, and the causers of deadly accidents were certainly outnumbered by them. That means that the cities of short-cutting were rather correction and rehabilitation centers. They were places of learning much rather than places of refuge.
Why until the death of the high priest?
An accidental killer had to stay in his city of short-cutting until the death of the high priest (Numbers 35:25, 35:28, 35:32, Joshua 20:6), which is an additional mystery, but it demonstrates that the exile of the killer had nothing to do with the anger of the victim's family and everything with atonement.
The annual Day of Atonement involved a set of rituals which included the famous scapegoat (Leviticus 16:8, 16:21-22), who would be charged with the transgressions of Israel and sent off into the wilderness to remove the sins from the people. It appears that when a high priest died, his son would take his place on the Day of Atonement, so that the son's inauguration would coincide with making atonement (Leviticus 16:32).
All this suggests that the goat could carry all sin except the gravest redeemable sin of all, which was accidental manslaughter. It appears that the high priest was personally charged with removing all accidental manslaughter that had happened during his tenure, and that with his own death.
The sole function of the entire priestly class was to teach the people the Law, and to provide ideal circumstances for the Law to be studied. When the carelessness of some fool caused the death of a colleague, the productivity of two men would be lost and the productivity of their extended families would be severely compromised. In a way, both the fool who should have paid better attention and the teachers who should have been more effective, shared the guilt of the accident.
The rule of the high priest also involved preventive legislation and safety measures, and an accidental death was in part made possible by his failing regime. That regime would end at his death, and the new high priest started his reign with a death toll of zero but also with the release of the fools whose unchecked foolishness had caused deaths during the previous regime.
Note the similarities between the verb קלט (qalat) and the verb חרם (haram).