Why is 11 really 10 according to Rabbi Ila TB Haggigah 21

With today’s daf TB Haggigah 21 we begin the third and last chapter of our massekhet. This chapter continues the discussion concerning ritual readiness (taharah-טהרה) and ritual unreadiness (tumah-טומאה). The first Mishnah of the third chapter actually begins on yesterday’s daf and continues on to today’s daf. The Mishna lists 11 different cases where the rabbis were more stringent concerning sacrificial food (kodesh-קּוֹדֶשׁ) than terumah (תְּרוּמָה).

For those of us who are old enough to remember Brooke Shields 1981 commercial when she said, “Nothing comes between me and my Calvin Kleins” can appreciate the following halakha. When immersing in a mikvah any interposition  (hatztizah-חֲצִיצָה) invalidates the immersion. Both the first case “that one may immerse vessels inside other vessels to purify them for teruma; but not for sacrificial food, for which one must immerse each vessel separately” and the fifth case “The characteristics of teruma are not like the characteristics of sacrificial food, as in the case of vessels that are used with sacrificial food, if one has a garment or vessel that is tied up he must untie it and dry it if there was any moisture on it, as both a knot and absorbed moisture are considered interpositions that prevent the water of the ritual bath from reaching the entire garment. And he may then immerse them, and afterward he may tie them up again if he wishes. But with regard to teruma he may, if he so desires, tie up the garment and then immerse it without any concern that the knot might be considered an interposition.” (Sefaria.org translation) are concerned about hatzitzah. Consequently, Rabbi Ila enumerates only 10 concepts because he consolidates the first case and the fifth case.

“The Gemara comments: Rabbi Ila here conforms to his standard line of reasoning in considering these two issues as one, as Rabbi Ila said that Rabbi Ḥanina bar Pappa said: They taught ten stringencies of sacrificial food here in this mishna, rather than the apparent eleven. The first five stringencies apply both to the sacrificial foods themselves and to non-sacred food that was prepared according to the standards of purity of sacrificial food, whereas the last five apply only to actual sacrificial food but not to non-sacred food that was prepared according to the standards of purity of sacrificial food. The fact that Rabbi Ila counts only ten cases in the Mishna shows that he considered the two cases discussed above to be of the same category, and therefore they are counted together as one stringency.” (Sefaria.org translation)

What is the significant difference between the first five cases and the second five cases? If the fear is real in the first five cases, then the ritual unreadiness, tumah, is forbidden on the Torah level, deoraoita-דאורייתא. The second five stringencies are just rabbinic legislation to give primacy to kodesh. There was a practical outcome if a person wanted to train himself and only eat all his food as if it were on the same level of sanctified food. “The Gemara explains Rabbi Ila’s statement. What is the reason for this distinction? With regard to the first five stringencies, which have a connection to impurity as defined by Torah law because ignoring them can lead to a case of impurity by Torah law as opposed to merely rabbinic law, the Sages decreed these stringencies both for actual sacrificial food and for non-sacred food prepared according to the standards of purity of sacrificial food. However, with regard to the last five, which do not have a connection to impurity by Torah law, as their entire impurity is based on a rabbinic decree, the Sages decreed these stringencies only for actual sacrificial food. But with regard to non-sacred food made according to the standards of purity of sacrificial food, the Sages did not decree these stringencies for such foods.” (Sefaria.org translation)