The pesukim(23:17-20) which discuss the selling of machpelah states twice that the land of efhfron belongs to Avraham,why the redundancy?
The Ramabam Holds like Rav Hai Gaon that land is not acquired by a Jew until he digs or makes a change to the property.If a Jew pays money to a non Jew the property leaves the non Jews reshus but does not enter the Jews until he does something to the land.
Now we can reconcile the redundancy. The fist time the Torah mentions that Avraham acquired the land it says in the eyes of the children of chet(they thought he wasn’t a Jew). Since he paid they thought he owned it. When the Torah mentions Avraham’s ownership the second time it mentions that Avraham buried Sarah his wife (he worked the land) and in this instance the Torah considered the land to be his. (meshech Chachma)