Avraham asked for the cave; why did Efron offer him the field as well?
Ramban #1: He taught Avraham that it was not correct for a great man like himself to own a burial plot and that the rest of the field belongs to somebody else. 1
Ramban #2: To trick him into buying the field as well. 2
Ohr ha'Chayim: Since the cave will be a cemetery, the field is not proper for anything.
Malbim: The enactment (refer to 21:8:1:3*) was for the honor of residents. Therefore, the only solution is to buy the entire field, and the cave is included. I sell to you a field for farming, with a cave. This does not look like a sale of a cemetery!
Ha'Emek Davar: Since he will be getting an entire field, he cannot request it for free.
What did Efron mean when he said 'No... !'
Rashi: He meant that he wanted to give the entire property as a gift to Avraham
Why did both Efron and Avraham (in Pasuk 13) use the past tense ("ha'Sadeh Nasati lach"and "Nasati Kesef ha'Sadeh")?
Rashi: Efron told Avraham that it was as if the field was given to him, to which Avraham replied that the money was prepared and it was as if he had given it to Efron. 1
Ohr ha'Chayim: I already resolved to give it to you.
Only he added "Take it from me", because, unlike land, which can change hands automatically, money must be handed over [Sifsei Chachamim]).
Why did Efron stress that he was giving the property to Avraham in front of the entire nation?
Ramban: He was pointing out that since everybody was present, Avraham did not need to fear that he (Efron) might deny the transaction or retract from it.
Ohr ha'Chayim: Avraham had expressed concern lest a neighbor contest the sale in the future, saying that a neighbor has first rights to buy (refer to 23:8:1:2) 1 . Everyone is here, so no one can claim this afterwards!
Malbim: All will consent, for you acquire the entire field (refer to 23:11:2:3).
Ha'Emek Davar: (a) Everyone knows that I give it to you 2 , and I will not retract. (b) In front of everyone I call it a gift
There, Ohr ha'Chayim said that Avraham was also concerned lest a creditor had a lien on it. Giving in front of the entire city did not dispel this concern. Perhaps there is a creditor in another city! (PF)
Ha'Emek Davar: He stressed "to you", to honor Avraham. I would not give it to anyone else, for any price!
What was Avraham's reaction to Efron's statement?
Ramban: Avraham did not take him at his word; even after having paid in full, he made a point of acquiring the field and the cave with a Kinyan Chazakah in full view of all the Bnei Ches, and of all the merchants and visitors who happened to be there.
Why did Efron say "Shema'eni"?
Ohr ha'Chayim: Understand my words and reason (for wanting to give to you the entire field).
Why did Efron repeat "bury your Mes"?
Malbim: I sell to you a field, with a cave to bury one Mes. This does not look like a sale of a cemetery! Afterwards, you may do as you please with your property (make the cave a cemetery).