'Thousands' in the Bible

and with him ten princes, one prince of a fathers' house for each of the tribes of Israel; and they were everyone of them head of their fathers' houses among the thousands of Israel.

Then the children of Reuben and the children of Gad and the half-tribe of Manasseh answered, and spoke to the heads of the thousands of Israel,

When Phinehas the priest, and the princes of the congregation, even the heads of the thousands of Israel that were with him, heard the words that the children of Reuben and the children of Gad and the children of Manasseh spoke, it pleased them well.