Genesis 23:17-20

So the field of Ephron in Machpelah, which was to the east of Mamre, the field with the cave that was in it and all the trees that were in the field, throughout its whole area, was made over to Abraham as a possession in the presence of the Hittites, before all who went in at the gate of his city. After this, Abraham buried Sarah his wife in the cave of the field of Machpelah east of Mamre (that is, Hebron) in the land of Canaan. The field and the cave that is in it were made over to Abraham as property for a burying place by the Hittites.