Let him sell me the cave of Machpelah that he owns, which is at the edge of his land. Let him sell it to me, at the full price, for a burial site in your midst.
Rav and Shmuel disagreed about the Cave of Machpelah: one said it consisted of two chambers, one within the other; the other said it was a chamber with an upper story. The Gemara explains the doubling, and Rabbi Yitzchak explains Kiryat Arba as the city of four couples buried there.
On the daf / in context: Eruvin 53a continues the discussion of the name and structure of the Me’aras HaMachpelah. Both views treat “Machpelah” as describing the physical layout of the cave rather than merely a place-name.
Type of Learning
Dispute (Rav / Shmuel — structure of the cave)
What Is Learned
The name Me’aras HaMachpelah is understood as referring to a doubled structure — either two chambers one within the other, or one above the other — consistent with the pairs buried there.