Num 35:25

וְהִצִּ֨ילוּ הָעֵדָ֜ה אֶת־הָרֹצֵ֗חַ מִיַּד֮ גֹּאֵ֣ל הַדָּם֒ וְהֵשִׁ֤יבוּ אֹתוֹ֙ הָֽעֵדָ֔ה אֶל־עִ֥יר מִקְלָט֖וֹ אֲשֶׁר־נָ֣ס שָׁ֑מָּה וְיָ֣שַׁב בָּ֗הּ עַד־מוֹת֙ הַכֹּהֵ֣ן הַגָּדֹ֔ל אֲשֶׁר־מָשַׁ֥ח אֹת֖וֹ בְּשֶׁ֥מֶן הַקֹּֽדֶשׁ׃

The assembly is to protect the manslayer from the hand of the avenger of blood. Then the assembly will return him to the city of refuge to which he fled, and he must live there until the death of the high priest, who was anointed with the holy oil.