Talmud for Makkot 2:7
נִגְמַר דִּינוֹ בְלֹא כֹהֵן גָּדוֹל, הַהוֹרֵג כֹּהֵן גָּדוֹל, וְכֹהֵן גָּדוֹל שֶׁהָרַג, אֵינוֹ יוֹצֵא מִשָּׁם לְעוֹלָם. וְאֵינוֹ יוֹצֵא לֹא לְעֵדוּת מִצְוָה וְלֹא לְעֵדוּת מָמוֹן וְלֹא לְעֵדוּת נְפָשׁוֹת. וַאֲפִלּוּ יִשְׂרָאֵל צְרִיכִים לוֹ, וַאֲפִלּוּ שַׂר צְבָא יִשְׂרָאֵל כְּיוֹאָב בֶּן צְרוּיָה, אֵינוֹ יוֹצֵא מִשָּׁם לְעוֹלָם, שֶׁנֶּאֱמַר (במדבר לה) אֲשֶׁר נָס שָׁמָּה, שָׁם תְּהֵא דִירָתוֹ, שָׁם תְּהֵא מִיתָתוֹ, שָׁם תְּהֵא קְבוּרָתוֹ. כְּשֵׁם שֶׁהָעִיר קוֹלֶטֶת, כָּךְ תְּחוּמָהּ קוֹלֵט. רוֹצֵחַ שֶׁיָּצָא חוּץ לַתְּחוּם וּמְצָאוֹ גוֹאֵל הַדָּם, רַבִּי יוֹסֵי הַגְּלִילִי אוֹמֵר, מִצְוָה בְיַד גּוֹאֵל הַדָּם, וּרְשׁוּת בְּיַד כָּל אָדָם. רַבִּי עֲקִיבָא אוֹמֵר, רְשׁוּת בְּיַד גּוֹאֵל הַדָּם, וְכָל אָדָם אֵין חַיָּבִין עָלָיו. אִילָן שֶׁהוּא עוֹמֵד בְּתוֹךְ הַתְּחוּם וְנוֹפוֹ נוֹטֶה חוּץ לַתְּחוּם, אוֹ עוֹמֵד חוּץ לַתְּחוּם וְנוֹפוֹ נוֹטֶה לְתוֹךְ הַתְּחוּם, הַכֹּל הוֹלֵךְ אַחַר הַנּוֹף. הָרַג בְּאוֹתָהּ הָעִיר, גּוֹלֶה מִשְּׁכוּנָה לִשְׁכוּנָה. וּבֶן לֵוִי, גוֹלֶה מֵעִיר לְעִיר:
One whose judgment was concluded without a high-priest, [i.e., if there were no high-priest], one who kills a high-priest, and a high-priest who kills, never leaves (his city of refuge), and (one who is exiled) goes out neither for testimony of mitzvah, nor for testimony in monetary litigation, nor for testimony in a capital case. Even if Israel needed him; even if he were a commander in Israel, like Yoav ben Tzeruyah, he never leaves, it being written (Numbers 35:25): "…that he had fled there" — there shall be his dwelling; there shall he die; there shall he be buried. Just as the city grants refuge, so does its tchum (its bound, two thousand cubits around the city) grant refuge. A slayer who went outside the tchum and was found by the blood-redeemer — R. Yossi says: It is a mitzvah for the blood-redeemer (to kill him), and everyone else is permitted to do so. R. Akiva says: The blood-redeemer is permitted to do so, and all others are not liable if they do so. [All others, aside from the blood-redeemer, who killed him outside his city of refuge, are not liable, it being written (Numbers 35:27): "He has no blood"; and the blood-redeemer is permitted to kill him (ab initio)]. If a tree stands in the midst of the bounds (of the city of refuge), and its boughs extend outside the bounds; or if it stands outside the bounds and its boughs extend within the bounds, all goes according to the boughs. [The Gemara explains that "also according to the boughs" is what is meant, i.e., If its trunk were within the bounds of the city of refuge, and its boughs extend outside the bounds, if he stands under the boughs, he is "absorbed," since its main part is within, and its boughs are regarded as an extension of the main part. And if the main part is outside, and the boughs, within, so that he may not kill him under the boughs, he may also not kill him near the main part, the main part being regarded as an extension of its bows for stringency (in this regard). If he killed within that city, he is exiled from one neighborhood to another (within that city). A Levite is exiled from one city to another.