Charles Ellicott Commentary Nehemiah 10:34

"And we cast lots, the priests, the Levites, and the people, for the wood-offering, to bring it into the house of our God, according to our fathers` houses, at times appointed, year by year, to burn upon the altar of Jehovah our God, as it is written in the law;" — Nehemiah 10:34 (ASV)

As it is written in the law. —Leviticus 6:12 prescribes that the fire on the altar should be kept burning by wood. But here we have the origin of the “feast of the wood-offering”—a special day, subsequently substituted for the “times appointed year by year.” The lot determined the order in which the various classes should supply the wood.