There is a possibility that they dragged it at that time - ספק גררוהו ההיא שעתא
Summary:
The בור was a רה"י and nevertheless the כהן is טהור because by a ספק הרגיל (such as גררוהו [or אכלוהו]), we are lenient by a ס"ס even ברה"י.
If there is a פותח טפח in a burrow it escapes from its opening to the adjacent area and if there is no פותח טפח it is בוקעת ועולה. The רגלי כהן were in the רה"ר, or alternately ברה"י if we assume that ספק אכלוהו is a ספק הרגיל.
Does not leave over on the thirteenth - בשלשה עשר לא משיירא
Summary:
There are three categories concerning גרירת חולדה;
A. Bread on the thirteenth; sometimes משייר and sometimes not משייר. Therefore, if we see the גרירת חולדה, then we are חושש; if we do not see the גרירת חולדה, then אין חוששין.
B. Bread on the fourteenth; always משייר. Therefore we are always חושש.
C. Meat; never משייר, therefore never חוששין.
That is comparable to the case of ‘nine stores’ - היינו תשע חנויות
Summary:
According to רש"י the case of ט' צבורין is concerning the obligation of בדיקה, however according to תוספות the issue is whether the piece is permitted to be eaten. It is considered קבוע if we see the mouse take it from the מקום הקביעות; otherwise it is פריש. It is considered קבוע מדאורייתא if the איסור is known. If it is not known במקומו then it is קבוע מדרבנן (and even פריש can be אסור, on account of the חשש that he will take מן הקבוע since it is not ניכר).
This is similar to the case of two sacks - היינו שתי קופות
Summary:
ר"ל maintains that we assume the שאני אומר only if there is a רוב. However ר"י maintains that even if there is no רוב we assume the שאני אומר. Our גמרא follows the view of ר"י.
In all the (following) cases the loaf was too large to be eaten by the mouse.
