Now these are the divisions of the sons of Aaron. The sons of Aaron; Nadab, and Abihu, Eleazar, and Ithamar.
Divisions — The several branches into which that family was divided.
 But Nadab and Abihu died before their father, and had no children: therefore Eleazar and Ithamar executed the priest's office.
Therefore, … — Were the only persons to whom the execution of that office was committed.
 And David distributed them, both Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar, according to their offices in their service.
Distributed — Allotting to each of them several times, wherein they should by turns have the government of holy ministrations.
 Thus were they divided by lot, one sort with another; for the governors of the sanctuary, and governors of the house of God, were of the sons of Eleazar, and of the sons of Ithamar.
By lot — That the disposal thereof might be of the Lord, and so all contention be prevented, as no man could be charged with partiality, nor could any say, they had wrong done them. In like manner Matthias was chosen to the apostleship by lot with prayer. "And I know not, says Mr. Henry, but it might be still used in faith, in parallel cases, as an instituted ordinance." Of God - Or rather, of the things of God, that is, of all persons ministering in the sanctuary, and of all holy ministrations done in it, and of all other matters of the Lord, as they are called by way of distinction from, the king's matters, 2 Chronicles 19:11.
 And Shemaiah the son of Nethaneel the scribe, one of the Levites, wrote them before the king, and the princes, and Zadok the priest, and Ahimelech the son of Abiathar, and before the chief of the fathers of the priests and Levites: one principal household being taken for Eleazar, and one taken for Ithamar.
One, … — Or, the chief of one house of the fathers was taken (by lot) for Eleazar (out of his family) and that which was taken after it was taken for Ithamar, out of his family. So the first lot fell to Eleazar, and the second to Ithamar, the third to Eleazar, and the fourth to Ithamar, so successively, 'till all the families of Ithamar had received their lots. And afterwards all the lots came forth to the rest of Eleazar's families, which were double in number to those of Ithamar.
 Now the first lot came forth to Jehoiarib, the second to Jedaiah,
Came — Out of the vessel in which all the lots were put together, and out of which they were severally taken.
 These were the orderings of them in their service to come into the house of the LORD, according to their manner, under Aaron their father, as the LORD God of Israel had commanded him.
These, … — 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.
 These likewise cast lots over against their brethren the sons of Aaron in the presence of David the king, and Zadok, and Ahimelech, and the chief of the fathers of the priests and Levites, even the principal fathers over against their younger brethren.
Over against — Answerable for number and order to those of the priests, so that there should be a course of the Levites for each course of the priests.