לְגֵ֣רְשׁ֔וֹן מִשְׁפַּ֙חַת֙ הַלִּבְנִ֔י וּמִשְׁפַּ֖חַת הַשִּׁמְעִ֑י אֵ֣לֶּה הֵ֔ם מִשְׁפְּחֹ֖ת הַגֵּרְשֻׁנִּֽי׃
Of Gershon was the family of the Libnites, and the family of the Shimeites; these are the families of the Gershonites.
Read kabbalistic (mystical) interpretation of Numbers 3:21: and classical mystical sources.