Deut 27:12

27:12 these . . . on Mount Gerizim to bless. There is no apparent reason for the precise tribal assignments. Here Levi is included among the regular tribes (even among the six that pronounced the blessings), although some of the Levites were to recite the curses the people would answer. The tribe of Joseph united Manasseh and Ephraim, so the enumeration follows the names of the twelve patriarchs rather than the later tribal divisions.