דברי הימים א כח:א פירוש: רש״י

And David assembled all the leaders of Israel These are the leaders, the leaders of the tribes, as it is written (above 27:16): “And over the tribes of Israel, the leader of the Reubenites was...”

and the leaders of the divisions These are the twelve divisions of the king, as above (27:1): “And the Children of Israel to their number, etc.”

and the leaders of the thousands as above.