'Oaks' in the Bible

And Abram moved his tent, and came and dwelt by the oaks of Mamre, which are in Hebron, and built there an altar unto Jehovah.

And there came one that had escaped, and told Abram the Hebrew: now he dwelt by the oaks of Mamre, the Amorite, brother of Eshcol, and brother of Aner; and these were confederate with Abram.

And Jehovah appeared unto him by the oaks of Mamre, as he sat in the tent door in the heat of the day;