These were the descendants of Levi by their families—the heads of families, registered individually by name—those twenty years of age or older who worked in the service of the house of the LORD.
Jewish Publication Society of America Version (JPS1917) - 1 Chronicles 23:24 >These were the sons of Levi after their fathers' houses, even the heads of the fathers' houses, according to their muster, in the number of names by their polls, who did the work for the service of the house of the LORD, from twenty years old and upward.