Midrash sobre Números 35:10

(Bamidbar 35:9-10) "And the L-rd spoke to Moses, saying: Speak to the children of Israel … When you cross the Jordan, etc.": What is the intent of this section (on the cities of refuge)? From (Devarim 4:41) "Then Moses set aside three cities on the east side of the Jordan," we know only of these. Whence is it derived that Moses commanded Joshua to set aside cities of refuge (on the other side)? From (Bamidbar 35:11) "then you shall designate cities for yourselves." Scripture speaks of (the time) after inheritance and settlement. — But perhaps, upon their entry to the land? It is, therefore, written (Devarim 12:29) "When the L-rd your G-d has cut down the nations, etc." Scripture speaks of (the time after inheritance and settlement). (Bamidbar 35:10) "When you cross the Jordan to the land of Canaan": From here R. Yonathan derived: The Jordan is not part of the land of Canaan. R. Shimon b. Yochai says (Ibid. 26:3) "at the Jordan. Jericho": Just as Jericho is part of Canaan, so is Jordan. (Ibid. 35:11) "Then you shall call out cities (arim) for yourselves." "Calling out" connotes "designation." "cities": I might think, large cities; it is, therefore, written "arim" (connoting small cities). If so, I might think villages. It is, therefore, written "arim." How was this implemented in effect? They were of such size as to have markets and a food store. "And there shall flee there a slayer": I might think, any slayer. It is, therefore, written "a slayer, one who smites a soul unwittingly." If "one who smites a soul," I would think, even one who wounds his father and mother (unwittingly, viz. Shemot 21:15). It is, therefore, written "a slayer, one who smites a soul," Scripture hereby excluding from exile one who (unwittingly) wounds his father and mother.