1 Chronicles (Author Compiled by Isaiah and Ezra from records of Nathan, Gad, Iddo, Ahijah, Jehu and others.)
Chapter 12
37And from beyond the Jordan, of the Reubenite, and of the Gadite, and of the half of the tribe of Manasseh, with all instruments of the host for battle, are a hundred and twenty thousand.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.