וּבְנֵ֥י מְרָרִ֖י מַחְלִ֣י וּמוּשִׁ֑י אֵ֛לֶּה מִשְׁפְּחֹ֥ת הַלֵּוִ֖י לְתֹלְדֹתָֽם׃
And the sons of Merari: Mahli and Mushi. These are the families of the Levites according to their generations.
Read midrashic interpretation of Exodus 6:19: and classical rabbinic exegesis.