1. These were the groups of Aaron’s sons: Aaron’s sons were Nadab, Abihu, Eleazar, and Ithamar.
2. But Nadab and Abihu died before their father did. Nadab and Abihu had no sons, so Eleazar and Ithamar served as the priests.
3. David separated the tribes of Eleazar and Ithamar into two different groups. He did this so that these groups could do the duties of work they were given to do. David did this with the help of Zadok and Ahimelech. Zadok was a descendant of Eleazar, and Ahimelech was a descendant of Ithamar.