The Yerushalmi (Meg 3:1, 24a in the Vilna ed.) tells of R’ Chiya, who was given funds to distribute to orphans and widows, but distributed them to talmidei chachamim – the Yerushalmi questions whether those monies must now be replaced.
ר' חייה בר בא אזל לחמץ ויהבון ליה פריטין למפלגא ליתמייא ולארמלאתא נפק ופלגון לרבנן מהו שיהא צריך להפריש תחתיהן
The classical meforshim (Pnei Moshe, Korban ha’Eidah) learn that the safeik of the Yerushalmi is whether R’ Chiya as gabei tzedaka has to make good on the funds that should have gone to those orphans and widows, or whether he fulfilled his responsibility as gabai irrespective of who he distributed the funds to.
However, the Rogatchover (T.P. Hil Meg, quoted in R’ Kasher’s Klalei Torah u’Mitzvah for lazy people like me) has a completely different understanding of the Yerushalmi. He explains that the money R’ Chiya collected was matanos la’evyonim for Purim and the safeik of the Yerushalmi is not whether R’ Chiya did his job, but whether the people who gave the money fulfilled their mitzvah or not – do they have to make up those funds and contribute extra for matanos la’evyonim or not? Do we say that so long as the money was used for any charitable cause, even for supporting talmidei chachamim, they are yotzei, or do we say that since the money was not used as intended for the seudas Purim of widows and orphans, they are not yotzei?
Sounds to me like the safeik of the Yerushalmi, according to the Rogatchover, revolves around exactly the same issue we raised in discussing R’ Yosef Engel’s chiddush yesterday. If matanaos la’evyonim is just another form of tzedaka, then who cares who gets the money? But if it is a unique mitzvas ha’yom, not a din tzedaka, there is room to say that it’s method of being given should follow the technical laws of matanah, as R’ Yosef Engel suggests, and that the money must specifically be used for the seudah.
One might go a step further: the Rambam (Meg 2:16) tells us, “Keitzad chovas seudah zu…” and spells out that one must eat meat and drink wine. He then continues in the next halacha, “V’kein chayav lishloach shnei manos…,” and in the following halacha, “V’chayav l’chaleik l’ani’yim…” From the word “V’kein,” from the “vav” of “v’chayav,” one could make the case that these three halachos are a one long explanation of that opening, “Keitzad chovas seudah…” In other words, the chiyuvim of mishloach manos and matanos la’evyonim are part and parcel of the mitzvas ha’yom of seudah -- not only must you eat, but you must provide others with food as well. Therefore, only if matanos la’evyonim are distributed for use on Purim for the seudah would one be yotzei properly, not if they are given for another purpose.
(I am a little hesitant to write this because I can’t remember if I saw it in the Chasam Sofer or Ksav Sofer and have not had a chance to double-check my memory, but I recall seeing chiddush that you would not be yotzei at all by giving mishloach manos to someone not making a seudah, which follows from this same line of reasoning. Also, no matter how expensive your themed mishloach manos are, if they consist of toys, styrofoam decorations, and all kinds of wonderful things that no normal human being could consume as food, it does not help the seudah.)