Matthew Poole and continuators on 2 Samuel 18:6

6 ¶ So the people went out into the field against Israel: and the battel was in the wood of Ephraim ,

So called, not from its situation in the Tribe of Ephraim, which was on the other side Iordan, as is evident; but from some memorable action or occurrent of the Ephraimites beyond Iordan; whether it was their killing of Oreb and Zeeb there, Iudg. 7. 25. and 8. 3. or, their slaughter by Iephthah, Iudg. 12. 5, 6. or, some other not mentioned in Sacred Scripture.