Tosefta for Numbers 3:29

מִשְׁפְּחֹ֥ת בְּנֵי־קְהָ֖ת יַחֲנ֑וּ עַ֛ל יֶ֥רֶךְ הַמִּשְׁכָּ֖ן תֵּימָֽנָה׃

The families of the sons of Kohath were to pitch on the side of the tabernacle southward;