Genesis 23:16-18

16And Abraham hearkened to Ephron; and Abraham weighed to Ephron the money that he had named in the ears of the sons of Heth — four hundred shekels of silver, current with the merchant.

17So the field of Ephron, which was at Machpelah, which was before Mamre, the field, and the cave that was in it, and all the trees that were in the field, that were in all its borders round about,

18were assured to Abraham for a possession before the eyes of the sons of Heth, before all who went in at the gate of his city.