Eruvin 98A

מני? רבי שמעון היא, דאמר: כל דבר שהוא משום שבות אינו עומד בפני כתבי הקודש. אימא סיפא רבי יהודה אומר: אפילו אין מסולק מן הארץ אלא מלא החוט גוללו אצלו. רבי שמעון אומר: אפילו בארץ עצמה גוללו אצלו —

who is the tanna of the Mishnah? It is R' Shimon, who said: Anything that is prohibited on Shabbat and its prohibition is not by Torah law, but rather is due to a rabbinic decree issued to enhance the character of Shabbat as a day of rest does not stand as an impediment before the rescue of sacred writings. But if it is the opinion of R' Shimon, say the latter clause of the Mishnah as follows: R' Yehuda says: Even if the scroll is removed only a needle breadth from the ground, he rolls it back to himself; and R' Shimon says: Even if the scroll is on the ground itself, he rolls it back to himself.

רישא וסיפא רבי שמעון, מציעתא רבי יהודה! אמר רב יהודה: אין, רישא וסיפא רבי שמעון, מציעתא רבי יהודה.

Is it possible that the tanna cited in the first clause of the Mishnah is R' Shimon, as claimed above, while it is explicitly stated that the last clause represents the opinion of R' Shimon, and yet its middle clause reflects the opinion of R' Yehuda? Rav Yehuda said: Yes, that is the correct, albeit unconventional, explanation. The first and last clauses are in accordance with the opinion of R' Shimon, while the middle clause of the Mishnah reflects the opinion of R' Yehuda.

רבה אמר: הכא באיסקופה הנדרסת עסקינן, ומשום בזיון כתבי הקדש שרו רבנן.

Rabba said that the Mishnah may be understood differently. Here, we are dealing with a threshold that is trodden upon by the public, and due to the potential degradation of the sacred writings the rabbis permitted one to violate the rabbinic decree. It would be disgraceful if people were to trample over sacred writings.