The residents of a large town may traverse an entire small town, but the residents of a small town may not traverse an entire large town. How so? One who was in a large town and placed his eruv in a small town, [or] in a small town and placed his eruv in a large town, may traverse its entirety and two thousand cubits beyond it. But R’ Akiva says: He has no more than two thousand cubits from the place of his eruv.