'Classes' in the Bible

And Jehoiada appointed the offices of the house of Jehovah under the hand of the priests, the Levites, whom David had set by classes over the house of Jehovah to offer up Jehovah's burnt-offerings, as it is written in the law of Moses, with rejoicing and with singing according to the directions of David.

and stand in the sanctuary for the classes of the fathers' houses, for your brethren, the children of the people, and according to the divisions of the fathers' houses of the Levites;

And they set apart the burnt-offerings to give them to the classes of the fathers' houses of the children of the people, to present them to Jehovah, as it is written in the book of Moses. And so did they with the oxen.