Priests AND Levites, Not Just Priests
Commentators clarify a potentially confusing part of the verse. While it lists 'twelve of the chiefs of the priests,' it then names Sherebiah and Hashabiah, who were Levites. Scholars explain that Ezra actually set apart twelve priests and twelve Levites (Sherebiah, Hashabiah, and ten others), creating a joint team of 24 men to guard the temple treasures.