2 Samuel 18:6-8
6-8The army took the field to meet Israel. It turned out that the battle was joined in the Forest of Ephraim. The army of Israel was beaten badly there that day by David's men, a terrific slaughter—twenty thousand men! There was fighting helter-skelter all over the place—the forest claimed more lives that day than the sword!
9-10Absalom ran into David's men, but was out in front of them riding his mule, when the mule ran under the branches of a huge oak tree. Absalom's head was caught in the oak and he was left dangling between heaven and earth, the mule running right out from under him. A solitary soldier saw him and reported it to Joab, "I just saw Absalom hanging from an oak tree!"