This is the cave in the field of Machpelah, near Mamre in Canaan, that Abraham bought from Ephron the Hittite as a permanent burial site.
So the field and the cave were transferred from the Hittites to Abraham for use as a permanent burial place.
Then, leaving her body, he said to the Hittite elders,
“Here I am, a stranger and a foreigner among you. Please sell me a piece of land so I can give my wife a proper burial.”
His sons Isaac and Ishmael buried him in the cave of Machpelah, near Mamre, in the field of Ephron son of Zohar the Hittite.