Now you see it and now you don’t TY Shekalim 20

Daf TY Shekalim 20 tells of Rav’s stringency concerning whether found meat is considered kosher or treif (neveilah). Beginning at the very bottom of the previous daf and continuing on daf 20: “Rav went down there to Babylonia, and he saw them acting leniently so he ruled stringently for them, as the Gemara proceeds to relate. A certain person went and wanted to wash his meat in the river and forgot some of it there and went on his way. He came back to retrieve the piece he had left behind and wanted to take it. Rav said to him: it is forbidden for you to eat that piece. For I say that perhaps the river washed away that piece that you left behind, and brought another piece that is from a neveilah in its place.” (Art Scroll translation)

 Rav’s ruling is based upon his principal “meat that was hidden from the eye- בשר שנתעלם מן העין” (See TB Hullin 95a) According to some poskim, this stringency only applies to a city with a mixed Jewish and non-Jewish population because of the fear of eating treif meat. If the city has only a Jewish population, the found meat would be permitted for consumption. Moses Maimonides rules that the stringency to prohibit “meat that was hidden from the eye” even in the case of an entirely Jewish city. (Mishneh Toorah, Maakhalot Asurot, 8:12)

 The Shulkhan Arukh also cites the opinion that there those who permit “meat that was hidden from the eye” if it was found in the place where it was left. Moses Isserles, who wrote a gloss for Ashkenazi Jews, writes that it is the custom to be lenient according to the last opinion including even if the meat was in the hands of a Gentile in a place where all the sellers were Jews selling kosher meat. (ויש מתירין בשר שנתעלם מן העין אם מצאו במקום שהניחו: הגה והמנהג להקל כסברא האחרונה ואפילו אם היה ביד עובד כוכבים במקום שכל המוכרים הם ישראלים המוכרים בשר כשר. ועיין לקמן סימן קי"ח:)

 If I’m not mistaken, meat that is shipped from one place to another, like from the whole seller to the retailer, is sealed with a special seal to prove that the meat is kosher and hasn’t been replaced with treif meat to avoid the problem of “meat that was hidden from the eye.”