Against the blood redeemer. Meaning that מגואל ["from the avenger"] refers to the blood redeemer. Rashi continues to explain which person is termed the blood redeemer, given the name “redeemer” could refer either to the redeemer of the murderer or to the redeemer of the victim. Therefore Rashi explains that he is a kinsman of the victim.

The three that Yehoshua placed. Rashi wishes to answer the question: Why did it write the number? Surely when it is written afterwards (v. 14), “three cities you shall give…” [Therefore] we see that there were a total of six. Rather, it was to teach that they did not provide refuge until all six were established.

Rife with murderers. You might ask: Surely the cities of refuge would only provide refuge for inadvertent killers, and it is illogical to say that Gil’ad was rife with inadvertent killers. The answer is that they were certainly intentional killers, however there were no witnesses and thus they claimed that they killed inadvertently. Consequently, they required three cities of refuge. Re’m. Another answer is that this refers to a matter detailed in Parshas Mishpatim (Shemos 21:13), “Hashem caused it to come to his hand” teaching that Hashem arranges for them to be at the same inn…” (see below). Here too it refers to the same matter. There were many murderers in Gil’ad who acted with intent but without witnesses, and in the land of Israel there were many inadvertent killers without witnesses. So what did Hashem do? He would arrange for them to be at the same inn, in Gil’ad, and the inadvertent killers from the land of Israel would inadvertently kill the intentional killers. For example, when [the murderer] was sitting beneath a ladder as Rashi explains there [the inadvertent killer would accidentally fall upon the murderer, killing him in front of witnesses]. Consequently, the intentional killers would be killed while the inadvertent killers would be exiled there in Gil’ad to these cities of refuge. Thus, it was necessary to have three cities of refuge in Gil’ad like in the entire land of Israel. (Divrei Dovid) answers the question with the Gemara in Perek Eilu Hen Hagolin (Makkos 10b): It was taught in a beraysa: Rabbi Yosi bar Yehudah says that initially both inadvertent and intentional killers go to the cities of refuge, and the Beis Din sends messengers to bring them [for judgment]. Whoever is liable for the death penalty is executed, as it says (Devarim 19:12), “The elders of his city shall send for him and take him from there…” Whoever is not liable is released, and whoever is liable for exile (i.e., city of refuge) is returned to the place [from where he was taken].

Bloody ambush. עקובה is in the sense of an ambush.

Of a size capable. כמיסת means “of a size.”

But it states. Meaning that when it is written, “If [he struck him] with an iron instrument… or if with a stone that can be held in the hand… or if with a wooden implement…” until “If [he pushes] out of hatred” (v. 20) perhaps it is referring to an inadvertent killer. And this was necessary [in contrast with the verses below] so that you would not say as follows: It is understandable if this refers to an inadvertent killer, that it would have had to say, “And if with an iron instrument” and all of the other cases that follow, in order to teach that he is liable for the death penalty, even if he killed inadvertently. But, if it refers to an intentional killer, what difference does it make whether he killed with an iron or any other instrument? Surely he is an intentional killer. However, when it is written afterwards (v. 21), “Or if in enmity…” until “But if suddenly” (v. 22) [it is clear that] these undoubtedly refer to an intentional killer.

With a stone. Rashi is answering the question: Why does Scripture write about “a stone” (v. 23)? Surely above it is also written about a stone, where it [apparently] also refers to an inadvertent killer. Rather, “This teaches that in its statements above…”

Large enough. You might ask: Surely it is written, “A stone that can be held in the hand” and Rashi explains that this is “large enough to fill the hand,” meaning that it is large enough to kill. The answer is that one phrase teaches that it is large enough to kill when one strikes, and one phrase teaches that it is large enough to kill when one throws it. For sometimes it would be large enough to kill when striking but not when thrown, and if one were to throw it and kill, I might have said that he was culpable. Consequently, we are informed that he is not culpable until it is large enough to kill when thrown. With this we can answer the question of Re’m who writes “I do not know…”

Even inside the cities of refuge. For here the Torah speaks about a premeditated killer, as Rashi explains above (v. 16). If Beis Din did not execute him and he exiled himself to a city of refuge without its authorization, then [the avenger] could kill him, even inside the city of refuge. For if not so, why does the Torah write “where ever he meets him”? Surely it had already written, “The blood avenger shall kill the murderer.”

He struck him. Without the additional phrase, “He struck him,” we would understand “without seeing” is associated with “which can kill” as if to say that he did not see his death. However this is not so, rather it means to say that he did not see when he struck him. Furthermore, without the additional wording the phrase, “Or even with a stone” would obviously be missing [a verb], since it should have said, “Or even struck with a stone.” For if it referred back to [the verb] “threw” (v. 22), the verse should have said או כל אבן ["or even a stone"].

While descending. Such as where one was rolling a roller downward and it fell upon a person and killed him, or where one was lowering a bundle and it fell upon a person, or one was descending a ladder and fell upon a person and killed him, [in all these cases] he is exiled.

While ascending is not exiled. If one was pushing a roller upward and it fell on a person and killed him, or one was raising a barrel and the rope broke and the barrel fell on a person and killed him, or where one was ascending a ladder and fell upon a person and killed him, he is not exiled. The reason is that because all of these [deaths] were as a result of moving upward and he was not obliged to be cautious.

That this [pitfall] not occur. According to the first interpretation there is the difficulty that it is written, “Until the death of the Kohein Gadol.” The verse is saying that the murderer will live after the death of the Kohein Gadol, since the Kohein Gadol would die sooner, but why would this be? Therefore, Rashi explains, “Because he should have…” However, according to the second interpretation there is the difficulty that even if the Kohein Gadol was punished with death for not praying, why should the murderer return home after the death of the Kohein Gadol? Therefore, he also brings the first reason.

Who anointed him. The verse implies that the murderer anointed the Kohein Gadol with the sacred oil, therefore one must say that this is one of the shortened passages…

So long [as it functions]. For it is written in Parshas Shoftim (Devarim 17:8), “You shall ascend to the place” which teaches that it is “the place” which confers authority. This means: At the time when the Great Sanhedrin of Yerushalyim sit in the Chamber of Hewn Stone [in the Temple, the lower] courts function outside the land and in other locations [within the land] are in effect.

The one who endeavors to kill him. Referring to the killer, because he had killed a person.

And was forewarned. Meaning that this is one of the shortened passages, and it is as if the verse had said if anyone strikes a person, meaning that he killed a person, he may not be killed unless there is testimony that he killed intentionally and that he was forewarned.

He cannot absolve himself. Meaning that this is one of the shortened passages, and it is as if the verse had said, “Do not accept atonement compensation for the life of a murderer who is wicked to incur the death penalty, to exempt him from death, for he must be executed.” Since in Parshas Mishpatim the Torah writes (Shemos 21:29), “If it was a goring ox… and it killed a man or woman, the ox shall be stoned and its owners shall also die,” [where his death] is at the hands of the heavenly court. This implies that just as his ox is liable for death, so too he is liable for death. Nonetheless, afterwards it is written (v. 30), “When an atonement compensation is imposed upon him, he must give a redemption of his soul,” which implies that if he was liable for the death penalty on account of his ox, he can absolve himself with money. Therefore, I would have thought that the same is true if he was liable for the death penalty on his own account, that he could absolve himself with money.

Like לנס. With a sheva below the [letter] lamed and a kamatz below the [letter] nun [לנס "one who has fled" rather than לנוס "to flee"], meaning that just as there is no redemption for the death penalty, so too there is no redemption for exile.

Do not bring evil. For the word חנופה [lit. "false flattery"] is not appropriate when referring to blood. With regard to the land this term is understandable, since חנופה would be appropriate if “land” is explained as referring to the inhabitants of the land, with whom false flattery is possible. However, regarding blood, it cannot be explained in this manner.