וְלֹֽא־תִסֹּ֤ב נַחֲלָה֙ לִבְנֵ֣י יִשְׂרָאֵ֔ל מִמַּטֶּ֖ה אֶל־מַטֶּ֑ה כִּ֣י אִ֗ישׁ בְּנַחֲלַת֙ מַטֵּ֣ה אֲבֹתָ֔יו יִדְבְּק֖וּ בְּנֵ֥י יִשְׂרָאֵֽל׃
So shall no inheritance of the children of Israel remove from tribe to tribe; for the children of Israel shall cleave every one to the inheritance of the tribe of his fathers.
Read midrashic interpretation of Numbers 36:7: and classical rabbinic exegesis.