BDB7725
[רִבֵּעַ] adjective pertaining to the fourth (in a series); — plural in phrase עַלֹשִֿׁלֵּשִׁים וְעַלרִֿבֵּעִים i.e. those belonging to the 3rd and 4th generations, Exod 20:5 ( E ) = Deut 5:9; Exod 34:17 ( J ), Num 14:18 ( J E ), compare 1 above