Judges 20:25

And Benjamin went forth against them out of Gibeah the second day,.... Flushed with the victory they had obtained the day before:

and destroyed down to the ground of the children of Israel again eighteen thousand men, all these drew the sword, were armed men; this, with the 22,000 slain the day preceding, made 40,000; the same number singled out from among them by lot to provide food for them, and is thought by some to be the case Deborah refers to, Judges 5:8 and is what is certainly intended in Hosea 10:9.