Who are the four families listed in Zechariah 12:12-13?
Rashi on Zechariah 12:12-13 points to 2 Samuel 5:14, which lists four sons born to David in Jerusalem: Shamua (called “Shimei” in Zechariah), Shovav (not mentioned in Zechariah), Nathan, and Solomon. Thus Zechariah first mentions the House of David in general, and then lists two of the families (Nathan and Shimei/Shamua) individually, as well as mentioning the family of Levi (the priests and Levites).
Ibn Ezra and RaDaK disagree with Rashi, and say that Nathan and Shimei were families that were well known in those days — not families descended from David. In any case, Shimei is not the Benjaminite who cursed David; many people by that name are mentioned in the Bible, including one of Levi’s grandsons, Mordecai’s grandfather, and several others in Kings, Ezra, and Chronicles.