And the elders of the city that is nearest to the slain man shall take a heifer that has never been worked and that has not pulled in a yoke.
Care had been taken by some preceding laws for the vigorous and effectual persecution of a wilful murderer (Deu 19:11 etc.), the putting of whom to death was the putting away of the guilt of blood from the land; but if this could not be done, the murderer not being discovered, they must not think that the land was in no danger of contracting any...
Commenting on Deuteronomy 21:1-9
And it shall be, that the city which is next unto the slain man,.... And so suspected, as the Targum of Jonathan, of the murder; or the murderer is in it, or however belonged to it: even the elders of the city shall take an heifer; of a year old, as the same Targum, and so Jarchi; and in this the Jewish writers agree, that...
Deu 21:3-4 This nearest town was then required to expiate the blood-guiltiness, not only because the suspicion of the crime or of participation in the crime fell soonest upon it, but because the guilt connected with the shedding of innocent blood rested as a burden upon it before all others.
Commenting on Deuteronomy 21:3-4