The gemara says that we learn from the word Makom that the arei miklat should be in the Machaneh Leviah (as Rashi says) so if so why does the gemara have to carry on to say l'Heichan Golin l'Machaneh Leviah but we already know that from the previous drasha of b'Mekmomcha so it seems like there is a repetition over here?
Benzi, London
This question is asked by Rav Shalom Shechter in "Yeshurun" vol 6 úùð"è) page 454.
He answers that there are 2 purposes of arei miklat (1) to protect the inadvertent murderer (2) to perform the Mitzvah of sending the murderer to the Arei Miklat.
It follows that even if the murderer is not afraid of the Goel Hadam he still has a Mitzvah to go to the refuge city.
Rav Shechter cites a proof, from 11b, that there is a Mitzvah to go to the Ir Miklat even if no protection from danger is involved. Abaye said that if the Rotzeach died before he had chance to go the city, we take his bones there. This is in order to fulfil the positive Mitzvah of going to the Ir Miklat.
Now we have pshat in the Gemara 12b. We learn from the word Makom that the Machaneh Leviyah protects the Rotzeach and the Goel Hadam may not attack him there. But we do not yet know that one performs a Mitzvah by going to the Machaneh Leviyah. That is why the Gemara adds "l'Heichan Maglin l'Machaneh Leviyah" to teach us that not only does the Machaneh Leviyah protect, but one also is mekayem the Mitzvas Aseh by going there.
Good Shabbos
Dovid Bloom
I want to try and suggest an answer to this question, bs'd, according to the Poshut pshat.
1) Firstly, it is worth looking at Rashi in Chumash Shemos 21:13. The posuk says "I will set aside for you a place". Rashi writes that this place was given even in the desert so that the Rotzeach b'Shogeg can flee there. Rashi continues and asks "which place absorbs the Rotzeach?" and answers "this is Machaneh Leviyah".
2) It seems from Rashi that the limud here works in 2 stages. (a) Firstly we must establish that even in the Midbar there were places to run to. After we know this we then want to know (b) which places these were, and we learn that they were Machaneh Leviyah.
3) If we look at our Gemara we might see that Rashi got the 2-stage limud from here. The Gemara learns from "where he will flee to" that there was golus also in the desert. This is (a) of Rashi in Chumash. The next stage of the Gemara is question (b) of Rashi in Chumash and again the answer is Machaneh Leviyah.
4) The limud from Makom comes in the Gemara before both (a) and (b). We could describe "Makom" as a private communication between Hash-m and Moshe Rabeinu. Rashi here writes that Hakodosh Boruch Hu promised Moshe. Rashi Zevachim 117a DH veSamti wrote that Hash-m hinted to Moshe. The limud from Makom does not yet represent a Mitzvah incumbent on Klal Yisrael.
5) I want to say that the reason that the Gemara asks l'Heichan Maglin is because the limud from Makom b'Mekomcha; that came in the Gemara before the 2-stage limud; is not a limud that we know yet to be binding on Klal Yisrael, since at this stage we only know that it is a private hinted promise to Moshe. What 'l'Heichan Maglin does for us is to be mechadesh that we can indeed learn out from the fact that Hash-m promised to Moshe that the arei miklat would be from the place of the Leviim, that this means that even before Moshe set aside the 6 arei miklat at the end of his life, the place to flee to in the midbar would also be Machanah Leviyah.
6) It is worth adding that the reason that our Gemara is somewhat unusual; as you perceived, Benzi; that the Gemara asks again about something that has already been stated, is because it is also unusual to have a Mitzvah that was given first as a hinted promise to Moshe. I am not aware of any other example of Hash-m hinting to Moshe on Har Sinai.
Shavua Tov
Dovid Bloom