Deuteronomy 19:3
דברים י״ט:ג׳
Deuteronomy 19:3
The Torah commands that you shall prepare the roads and divide the borders of your land into three parts, so that the murderer can flee there. Chazal read this as requiring the roads to the cities of refuge to be made ready and accessible.
תָּכִ֣ין לְךָ֮ הַדֶּ֒רֶךְ֒ וְשִׁלַּשְׁתָּ֙ אֶת־גְּב֣וּל אַרְצְךָ֔ אֲשֶׁ֥ר יַנְחִֽילְךָ֖ יְהֹוָ֣ה אֱלֹהֶ֑יךָ וְהָיָ֕ה לָנ֥וּס שָׁ֖מָּה כׇּל־רֹצֵֽחַ׃
You shall survey the distances, and divide into three parts the territory of the country that the ETERNAL your God has allotted to you, so that any manslayer may have a place to flee to.—