(Mishnah): This is like it was taught, that an Oni [who lacks bread, like this traveler] can be Me'arev through walking;

R. Meir says, only an Oni can do so;

R. Yehudah says, the same applies to an Ashir. An Eruv with bread is a leniency for Ashirim, so they need not walk.

(Gemara): R. Meir holds like the primary Eruv is a loaf. Why did they say that one may be Me'arev with his feet? It is to be lenient for an Oni who does not have a loaf.

R. Yehudah holds like the primary Eruv is with his feet. Why did they say that one may be Me'arev with a loaf? It is a leniency for an Ashir, so he need not walk.

Even though R. Yehudah says that the primary Eruv is with his feet, one may not sit in his house and say "I acquire my Shevisah in the place Ploni'';

Rather, he goes out to the field, and says "I acquire my Shevisah in place Ploni'', and delays there until dark. He returns to his city.

Support (Beraisa): A case occurred with the families of Beis Dimah and Beis Guryon. They used to give dried figs to Aniyim in famine years. Aniyim of Sichin went out and were Me'arev through their feet and delayed there until dark;

The next day, they entered and ate there, and returned. Everything that they did, they did according to Chachamim.