Cross reference
1 Chronicles 5:18
18 There were forty-four thousand, seven hundred and sixty of the sons of Reuben and of the Gadites and of the half-tribe of Manasseh, all strong men, expert in the use of the body-cover, the sword, and the bow, and in the art of war, all able to take up arms.
Numbers 1:3
3 All those of twenty years old and over, who are able to go to war in Israel, are to be numbered by you and Aaron.
Joshua 4:12-13
12 And the children of Reuben and the children of Gad and the half-tribe of Manasseh went over armed before the children of Israel as Moses had said to them:
13 About forty thousand armed for war went over before the Lord to the fight, to the lowlands of Jericho.