Reference for I Chronicles 6:48

לִבְנֵ֨י מְרָרִ֜י לְמִשְׁפְּחוֹתָ֗ם מִמַּטֵּ֣ה רְ֠אוּבֵן וּֽמִמַּטֵּה־גָ֞ד וּמִמַּטֵּ֤ה זְבוּלֻן֙ בַּגּוֹרָ֔ל עָרִ֖ים שְׁתֵּ֥ים עֶשְׂרֵֽה׃

Unto the sons of Merari were given by lot, according to their families, out of the tribe of Reuben, and out of the tribe of Gad, and out of the tribe of Zebulun, twelve cities.