'Set Apart' in the Bible

Then I set apart twelve of the chiefs of the priests, even Sherebiah, Hashabiah, and ten of their brothers with them,

The children of the captivity did so. Ezra the priest, [with] certain heads of fathers' [houses], after their fathers' houses, and all of them by their names, were set apart; and they sat down in the first day of the tenth month to examine the matter.