וַיִּֽהְיוּ־אֵ֥לֶּה בְנֵֽי־לֵוִ֖י בִּשְׁמֹתָ֑ם גֵּרְשׁ֕וֹן וּקְהָ֖ת וּמְרָרִֽי׃
And these were the sons of Levi by their names: Gershon, and Kohath, and Merari.
Read kabbalistic (mystical) interpretation of Numbers 3:17: and classical mystical sources.