Genesis 23:17-21

So Ephron’s field, which was in Machpelah, which faced Mamre, the field and the cave which was in it, and all the trees which were in the field, that were within all the confines of its border, were deeded over

to Abraham as a possession in the presence of the sons of Heth, before all who entered the gate of his city.

After this, Abraham buried his wife Sarah in the cave of the field of Machpelah facing Mamre (that is, Hebron), in the land of Canaan.

So the field and the cave that was in it were deeded over to Abraham for a burial site by the sons of Heth.