John Wesley on 1 Chronicles 24:19

These, &c. - In this order and method they were to come to perform the offices of the temple. To come - To come into the temple every sabbath - day, and to continue there 'till the next sabbath, when they were relieved by others. Aaron - Under the direction of the high - priests, whom he calls Aaron, because he represented his person and executed his office, and their father, because of the authority which by God's appointment he had over them.