Numbers 35:32

And, do not accept atonement compensation for one who has fled to his refuge city. For, someone who fled to a refuge city because he killed inadvertently, is not absolved from exile with money, by paying atonement compensation so that he may return and dwell in the land before the kohein dies.

לָנוּס . Like לְנָס, as in שׁוּבֵי מִלְחָמָה, “who returned from battle.” Similarly, נוּגֵי מִמּוֹעֵד, “who were excluded from the festivals.” Similarly, כִּי מֻלִים הָיוּ, “for they were circumcised.” Just as one says שׁוּב concerning someone who has already returned, and מוּל concerning someone who was already circumcised, so does one say לָנוּס concerning someone who has already fled. He is called נוּס as if to say מֻבְרָח, “has fled.” But perhaps you might interpret לָנוּס as לִבְרוֹחַ,”to flee,” and explain “do not accept atonement compensation” “for someone who must flee,” and absolve him from exile? Then I do not know how it could say “so that he may return and dwell in the land,” when he did not yet flee — from where shall he return?

Neither may you take ransom for him who hath fled to his city of refuge, so as that he may return to dwell in the land before the time of the high priest's decease.

ולא תקחו כפר, “and you are not to accept a ransom, etc.” if a deliberate killer had fled to a city of refuge, you must remove him and bring him to trial and convict him and carry out the death penalty. We know that Yoav the chief general of David had taken refuge and had held on to the corners of the altar, but had been removed from there and had been executed for the murder of Avner in peace time, in accordance with Exodus 21,14. David had not felt politically strong enough to carry out this penalty, but he had commanded his son Solomon to do so in due course, as if he would allow him to die in his sleep he would forfeit his share in the world to come, something David did not want to have on his conscience. (Kings I 2,28) Yoav was a very wise man, even among the senior members of the Supreme Court (Samuel II 23,8). According to Bamidbar Rabbah 23,13 and the commentators on that, he had been aware that the altar would not protect him against extradition, (seeing this had been spelled out in the Torah and most children under the age of ten had been aware of this.) He supposedly was aware that anyone executed by the Court for a capital offence was not allowed to be buried with his forefathers, and this would be an everlasting shame, and this is why he tried to escape death at the hands of the Court. When B’nayahu who had been assigned the task of arresting him heard this, he related it to King Solomon, who therefore decided to have him killed on the spot so that he could be buried with his forefathers. (Kings I 2, 30-31) David’s instructions to his son had been not to let him die peacefully, without specifying by what method he was to die. (Verse 5 in that chapter) According to our author, what David referred to when he told his son Solomon that Yoav had done something treacherous to him personally for which he was also guilty of the death penalty, referred to a different occasion, i.e. to Yoav having exposed Uriah hachitti, the first husband of Bat Sheva, to almost certain death in the war against the Ammonites. When Uriah was killed the other soldiers were very angry with Yoav their commander for having allowed a hero such as Uriah to be unnecessarily exposed. Thereupon Yoav showed his soldiers a letter that he had received from King David in which the king who had sat out that battle at home, had instructed him specifically to see to it that Uriah would be killed during a battle. Revealing the King’s secret to one and all was a sin for which Yoav was …