שָׁל֥וֹשׁ עָרִ֖ים תַּבְדִּ֣יל לָ֑ךְ בְּת֣וֹךְ אַרְצְךָ֔ אֲשֶׁר֙ יְהוָ֣ה אֱלֹהֶ֔יךָ נֹתֵ֥ן לְךָ֖ לְרִשְׁתָּֽהּ׃
你要在永恆者你的上帝賜給你、使你得為產業的地中,為自己分定三座城。
Sforno
שלוש ערים תבדיל, after Moses had explained the function of the judges, the king, the priests, and the prophets, Moses now details some of the tasks that fall under the jurisdiction of the judges, among them the establishment of the cities of refuge, the boundaries of the land, the examination of witnesses to establish that their testimony is truthful and accurate, and that they are acceptable as witnesses. Next, he deals with the tasks that fall within the competence of the king, such as leading the nation in war, especially aggressive wars beyond the boundaries of the land of Israel. (20, 1-9) The priests also have a role to play during the preparation of what are termed מלחמת רשות, “halachically permissible wars,” although they are not fought in order to repel invaders. The priests and judges cooperate in some of their duties, especially the עגלה הערופה, the calf killed when a murder in the field was unresolved. (21,1-9)
Rabbeinu Bahya
שלש ערים תבדיל לך בתוך ארצך, “Three cities you shall set aside for yourself in the midst of your land;” together with the three towns which Moses had already designated as cities of refuge on the east bank of the Jordan as reported in Deut. 4,41-43, this makes a total of 6 such cities. It is essential that these cities are regular, populated cities with all the normal amenities of a city, seeing the Torah wrote in verse 3 תכין לך הדרך, “prepare the way for yourself,” and the Talmud Makkot 10 understands these words to mean that signs with the word מקלט, “refuge,” must be posted on all the roads leading to such cities. This is in order for the unintentional killer not to lose time while trying to escape the vengeance of the slain man’s family. On Psalms 25,8: “Good and upright is the Lord; therefore He shows the sinners the way,” the sages say that these signs are designed to help unintentional sinners seeing their sin was inadvertent. We have another verse along similar lines in Job 36,22: “See, G’d is beyond reach in power; Who governs like Him?” The author refers to the unique attribute of G’d who helps the inadvertent sinner to rehabilitate himself.
Rabbeinu Bahya
The reason why the Torah continues with: “you shall divide your territory into three parts is that the cities of refuge should be situated so that their location effectively divides the land into three parts which are equi-distant from one another.