Numbers 10:4
If only one of them is sounded, then the chiefs, the heads of the thousands of Israel, are to come to you.
Exodus 18:21
But for the rest, take from among the people able men, such as have the fear of God, true men hating profits wrongly made; and put such men over them, to be captains of thousands, captains of hundreds and of fifties and of tens;
Numbers 7:2
Then the chiefs of Israel, the heads of their fathers' houses, made offerings; these were the chiefs of the tribes, who were over those who were numbered.
Numbers 1:4-16
And to give you help, take one man from every tribe, the head of his father's house.
Deuteronomy 1:15
So I took the heads of your tribes, wise men and respected, and made them rulers over you, captains of thousands and captains of hundreds and captains of fifties and captains of tens, and overseers of your tribes.