Charles Ellicott Commentary 2 Samuel 18:6

"So the people went out into the field against Israel: and the battle was in the forest of Ephraim." — 2 Samuel 18:6 (ASV)

The wood of Ephraim. —No wood of Ephraim on the eastern side of the Jordan is mentioned elsewhere in Scripture. Yet it is clear that the battle must have been on that side of the river for the following reasons:

1. Both armies were on that side beforehand, and there is no mention of their crossing;
2. David remained in Mahanaim (2 Samuel 18:3–4) with the reserves, for the purpose of aiding the army if needed;
3. He there received the news of Absalom’s death (2 Samuel 18:24–33);
4. The army returned there after the battle (2 Samuel 19:3); and
5. David had to cross the Jordan on his final return to Jerusalem, and was met at the crossing by the tribes (2 Samuel 18:15 and following).

There is really no difficulty except for what arises from our ignorance of local names. The narrative clearly implies that there was a “wood of Ephraim,” otherwise unknown, on the east of the Jordan.