Are there any sources explaining why these two peoples were not expelled like so many others?
וְלֹ֤א הוֹרִ֙ישׁוּ֙ בְּנֵ֣י יִשְׂרָאֵ֔ל אֶת־הַגְּשׁוּרִ֖י וְאֶת־הַמַּעֲכָתִ֑י וַיֵּ֨שֶׁב גְּשׁ֤וּר וּמַֽעֲכָת֙ בְּקֶ֣רֶב יִשְׂרָאֵ֔ל עַ֖ד הַיּ֥וֹם הַזֶּֽה׃ Nevertheless the children of Israel did not expel the Geshuri, nor the Ma῾akhati: but the Geshuri and the Ma῾akhati dwell amidst Yisra᾽el until this day