Targum for Numbers 4:29

בְּנֵ֖י מְרָרִ֑י לְמִשְׁפְּחֹתָ֥ם לְבֵית־אֲבֹתָ֖ם תִּפְקֹ֥ד אֹתָֽם׃

As for the sons of Merari, thou shalt number them by their families, by their fathers’houses;

Targum Jonathan on Numbers