These are the divisions of the sons of Aaron The several branches into which that family was divided. Therefore Eleazar and Ithamar executed the priest's office Their brethren being dead, and leaving no issue, they and their sons were the only persons to whom the execution of that office could be committed according to the law.
Related Commentaries of 1 Chronicles 24:1
1 Chronicles 24:1-2
1 Now these are the divisions of the sons of Aaron. The sons of Aaron; Nadab, and Abihu, Eleazar, and Ithamar.
2 But Nadab and Abihu died before their father, and had no children: therefore Eleazar and Ithamar executed the priest's office.