1) The gemara says that Rav said "v'chein l'eruv" on some tannaic statement about maaser ani. Rashi explains the gemara's question that the mishna and the braisa don't disagree with each other at all so what's the difference on which one we put the statement. I don't understand that. It seems like there is a machlokes. The braisa says that the shiur for peaches is 5, for esrog is 1 etc. and the mishna says the shiur for all fruit is the amount to sell and buy food for two meals. Are we saying that's the same shiur? Doesn't sound like it.
2) The overriding principle is that it must be two meals worth and we don't look at the value. Why would Abba Shaul in the mishna look at how much you could sell the fruit for? I guess I don't have a problem with Abba Shaul looking at the value because he's talking about tzedaka but how could we extend that shiur to eruvin? Eruvin has nothing to do with value!
David G, Baltimore, US
Dear David
Shalom and thanks for your excellent questions. Rashi points out the Gemorah on 29b "That which is a dip requires an amount to serve as a dip for two meals. That which is not a dip requires two full meals of the food". The Braisa is referring to foods, which serve as a dip, while the Mishnah is dealing with foods, which do not serve as a dip. So what is the explanation of Abba Shaul's statement you ask? The Gr"a in Sh'nos Eliyahu (Pe'ah 8:5, Long Peirush) explains that Abba Shaul was referring to such fruits which do not serve as a dip, but also cannot be eaten as an entire meal. In such a case the only way they can serve for an Eiruv is if the value of the fruit is at least Four Issarim, enough to purchase two meals. Clearly the Gr"a was bothered by your questions.
Incidently, the Rambam in Hilchos Matnas An'yim quotes the opinion of Abba Shaul, while in Hilchos Eiruvin he does not.
Thanks again.
Yehuda Landy