The gemara says Ki b'Ir Miklato Yeshev Ir she'Kalataso Kvar. So the gemara wanted to know 2 things, that where is the mekor that a Levi can go to a different neighborhood in his own city and also what is the mekor that a regular person who kills goes from one neighborhood to another, and the gemara answers that we darshun it from this passuk.
My question is that all we see from this passuk is that a city which has provided refuge once before can provide refuge again just in a different neighborhood, which only applies where a yisroel killed in the arei miklat however we don't see that someone who actually lives in arei miklat i.e. a levi, and it has never provided him refuge before (since he has never killed someone) has to go to a different part of that neighborhood so how do we see this from this passuk?
(I'm not sure if the ritva asks this in the middle of DH mi'Kan but I'm not sure if he says an answer)
Benzi, London
The Ritva cites Rashi Zevachim 117a [in our text of Rashi there this does not appear] that the scenario discussed here is one where the levi had already exiled to that district because of a previous murder, and then he killed again. The district absorbs him, and he must exile from one neighbourhood to another neighbourhood within the same district.
According to the Ritva's text of Rashi Zevachim, the levi has in fact already killed someone.
KOL TUV
Dovid Bloom
1) There is another way of learning this sugya given by the Rambam, in Hilchos Rotzeach 7:5. He writes that if a Levite killed someone outside of the Levite cities, and then fled to his own Levite city, this city absorbs him. The Chofetz Chaim, in Likutei Halchos here, in Ein Mishpat #5, printed at the bottom of the page, writes that the words ù÷ìèúå ëáø used by the Gemara, mean that the city had already "absorbed" him, to live there. We see that ù÷ìèúå does not have to mean that the city accepted him as a place of refuge as a murderer, but in fact ÷ìéèä can refer to any occasion when a person finds his dwelling in a certain place.
2) We often find that the word ÷ìè is a general word meaning that something is absorbed. See, for instance, Gemara Shabbos end 4a ÷ìåèä ëîé ùäåðçä that if an object is in the air place it is equivalent to resting on the ground. Similalry the levi had already "rested" in this city and lived there.
Behatzlochoh Rabah
Dovid Bloom