Numbers 3:29

משפחת בני קהת יוחנו … תימנה THE FAMILY OF THE SONS OF KOHATH SHALL ENCAMP … SOUTHWARD — and next to them was the division of Reuben who, too, were encamped in the South (cf. Numbers 2:10) — “Woe to the wicked, woe to his neighbour!” It was on this account (on account of the friendship caused by this proximity) that some of them (the Reubenites) — Dathan and Abiram and 250 men (who were also mostly Reubenites, cf. Rashi on Numbers 16:1) — were punished together with Korah and his congregation, (cf. Numbers 16:32 ff.), because they were dragged into the quarrel with them (cf. Midrash Tanchuma, Vayera 12).

מִשְׁפְּחֹ֥ת בְּנֵי־קְהָ֖ת יַחֲנ֑וּ עַ֛ל יֶ֥רֶךְ הַמִּשְׁכָּ֖ן תֵּימָֽנָה׃

The families of the sons of Qehat shall pitch on the side of the tabernacle southward.